By Lois Levin/ Special To The Tab
Those who braved the cold on Feb. 27 to hear MIT Professor Kerry Emanuel's
Environmental Speaker Series lecture at the Newton Library were captivated by his
clear presentation of complex scientific data from his climate modeling research.
Dr Emanuel's data shows that the intensity of
hurricanes in the Atlantic has grown dramatically -
doubled - in the past 30 years. This is due largely to
human activity. We have released enormous amounts
of greenhouse gases into the atmosphere by burning
oil and coal to create energy to power factories, heat
our homes and run our automobiles. We have
warmed the oceans, including the areas where
powerful storms are formed, and this translates
directly into more powerful hurricanes, with serious
consequences for coastal areas.
New England is highly vulnerable to hurricanes, which
have occurred at a remarkably steady rate for
centuries, averaging one every five years. As these
storms continue to grow more intense, they place us
at increasingly greater risk. Therefore, while we work
to address global warming, we must also empower
public agencies to plan for and cope with these
storms, which expose us to great physical danger and
financial risk. Insurance companies are already
refusing to provide coverage for storm damage in
many coastal areas.
The lecture, sponsored by the Green Decade Coaltion, will be aired on NewTV later
this spring.
This article is archived at www.greendecade.org/tabarchive.asp.
Wednesday, April 5, 2006
Hurricane man blows into town
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Frozen by uncertainty
By Eric Olson/ Special To The Tab
Global warming is upon us. Even the oil companies tell us so. BP, formerly known as
British Petroleum but now officially just "BP" (after spreading the rumor they wanted to
stand for "Beyond Petroleum") is running full-page ads in major newspapers
encouraging people to take the time to calculate their carbon footprint. The only
reason anyone would take the time is if they first believed there was some problem
with their carbon footprint, i.e., specifically carbon dioxide, the heat-trapping gas
formed whenever a fossil fuel is burned. Climate scientists have been fretting for a
couple of decades now that our species' emissions of billions of tons of CO2 per year
could warm up the planet, and both their models and their observations point clearly
now in that direction. So it is a great relief to see at least some of the major
beneficiaries of our carbon-intensive economy are finally encouraging consumers to
take note.
Let's say you do use the BP calculator or others like it to calculate your footprint. You
provide information on your household heating and air conditioning, your electricity
consumption, your mileage and miles driven, add in a plane trip or two, and don't
forget the hot water heater. What did you get? Between 15 and 20 tons per year? Are
you surprised that I guessed so close? It's not hard. Energy geeks all know that the
typical American house generates just over 13 tons annually, and we just add in 5 to
10 additional tons for transportation. Plane travel is especially costly by this measure.
Now what? This is the question of the decade. There is a great deal of uncertainty
about what if anything we can do on a personal level. Consider first the climate itself:
This is an unpredictable beast and has changed over the millennia all on its own.
There is a slim chance that it will either autocorrect (maybe more clouds will form and
will block the sun) or an act of God will save us at least temporarily (ash from large
volcanic eruptions also block the sun). A second rescue could come from our own
ingenuity: Surely we will come up with something - a cheap fuel from our own
garbage, cold fusion, vastly superior yet cheaper solar panels, etc. A third option is to
turn to the government and shout, "Make everyone suffer equally! Only then will I
accept sacrifice." Finally we could just be resigned to our fate. After all, maybe a
warmer world won't be so bad, really. We could just ride it out and send food to the
people suffering the worst consequences.
A hard-nosed economist, confronted with such uncertainty, might argue for a "wait but
watch closely" approach. If you act too soon, goes this reasoning, you may regret it
when some better option comes along. This sounds sensible, as does so much of
what economists say, but in light of the stakes involved (many species threatened with
extinction, 17% of the land area of Bangladesh to be lost with just a 1-meter rise in
sea level, hurricane intensity in the Atlantic up sharply over the past 30 years), a better
description of this response is "frozen by uncertainty". The deer-in-the-headlights
image comes to mind.
A middle ground is to do SOMETHING, even if it's small. Like get yourself down to
Swartz Hardware in Nonantum and check out their amazingly low prices on compact
fluorescent bulbs (full disclosure: I have no financial interest in that store). This could
be your Step One. Did you know that a single one of these twisty bulbs saves you
over $50 over its seven-year lifetime? Even if they still cost $10 they would be worth it,
but their cost is just a couple of bucks now, and the light quality has improved over
that of earlier versions.
As for Step Two, how about that $50 I just saved you, two lines back? Use that money
to support new renewable, clean electricity generation in New England. There's an
astonishing way to do this, and it gets your money multiplying all over the place.
Here's how it works: The government has already imposed a tiny clean power charge
on our utility bills. Look closely at your NStar bill and you'll see it. This money flows to
an entity called the Renewable Energy Trust Fund, which is charged with encouraging
new clean power (solar, wind, etc.) for the state. If you contribute $50 to support clean
power, the Trust fund will release an equivalent amount back to the City of Newton,
and the City has committed to spending this money on educational solar panel
displays on our public schools. (Oak Hill Middle School will be the first recipient, slated
for this summer.) Then the Trust releases a second $50 match, to support energy
efficiency projects in low-income housing in the state, wherever the need is greatest.
Finally, since this is a donation, you get a tax deduction for it, 100 percent of it. So you
can support new clean power, help put solar panels on a school, make a low-income
family a bit warmer next winter, get a tax deduction, and lo, it's free money to begin
with, because you bought the bulb at Swartz. Would you like to buy a second bulb?
To get going on this and join the growing throng of people voting with their pocket
books for renewable power, call the Mass Energy Consumers Alliance at 617-524-
3950 ext. 129, and ask to speak with Janna Cohen-Rosenthal. You may want to do
those other things - wait and watch closely, shout at the government, etc. - but the first
step is to crack through your own frozen uncertainty and support clean energy. One
lightbulb and one phone call at a time.
Eric J Olson, PhD, is Chairman of the Newton Citizens' Commission on Energy. He
teaches in the Sustainable International Development program, Heller School of
Social Policy & Management, Brandeis University.
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The Dilution Effect
By Jill Hahn / Special To The Tab
Here’s a story about a blacklegged tick, a white-footed mouse, an unpleasant
bacterium, and how reducing biodiversity in our own backyards can literally make us
sick.
Lyme disease, which now accounts for about 90
percent of the vector-borne disease (spread by an
animal carrier) in the U.S., is caused by the
bacterium Borrelia burgdorferi, transmitted by the
bite of an infected blacklegged tick, Ixodes
scapularis. A new-born tick does not carry the
bacterium. In order to acquire the bacterium, the
larval tick must take its blood meal from an infected
animal. And here’s where the I. scapularislarvae are
the kind of eaters you wish your children were: they
are not picky. They will feed on a wide variety of
mammalian, bird, or even reptile hosts. The larva
takes one blood meal from the host it happens to
encounter, and then molts into its next stage, called
a nymph.
Most people contract Lyme disease from the nymphal stage of the blacklegged tick,
partly because the nymph is small and hard to spot, partly because it is active in June
and July, when we’re likely to be out enjoying the woods.
What determines whether the nymphal tick that just bit you is likely to give you Lyme
disease? Dr. Richard Ostfeld, senior scientist at the Institute of Ecosystem Studies
(Millbrook, NY), conducted a series of elegant, if messy, experiments to find out. Since
a nymph can only acquire B. burgdorferi during its larval meal, Dr. Ostfeld’s first task
was to determine whether feeding on different animals resulted in differing proportions
of infected nymphs. To do this, he and his colleagues trapped individuals from every
potentially important bird and mammal species in his study site in Duchess County,
NY. This list included deer, robins and other songbirds, white-footed mice, chipmunks,
raccoons, possums, skunks, shrews, and squirrels. The animals (deer excepted) were
caged for 72 hours. Any tick larvae attached to them fell off into pans of water under
the cages. They were collected (a dirty job, because more than just ticks dropped into
those pans during the 72 hours) and tested for the presence of the Lyme disease
bacteria.
Dr. Ostfeld discovered that over 90 percent of the ticks that fed on white-footed mice
tested positive for B. burgdorferi. 40-55 percent of the ticks from shrews or chipmunks
tested positive, and the proportion of positive ticks collected from the other species
ranged from around 15 percent to less than 2 percent. So the host species a larval tick
2
Photo courtesy of Frontiers in Ecology
and the Enivronment
White-footed mouse female
and pups
fed on dramatically affected whether the resulting nymph would be able to transmit
Lyme disease.
Since different species of animal have differing abilities to pass the Lyme disease
bacterium to the tick, this suggests that increased host biodiversity might lower the
prevalence of infected ticks. Dr. Ostfeld dubbed this hypothesis the Dilution Effect.
Ecologists know that, as you fragment forest into smaller and smaller pieces, the
number of animal species found in those forested "islands" declines. If the Dilution
Effect holds true, then the proportion of infected nymphal ticks should increase as
forest area goes down and biodiversity decreases. Dr. Ostfeld and his colleagues set
out to test that prediction.
They measured the density of nymphal ticks in forest fragments of different sizes
(ranging from less than two acres to almost 19 acres) by dragging drop cloths through
the forest and counting the number of nymphs collected. When Dr. Ostfeld tested the
ticks, he discovered that, as the Dilution Effect predicted, the proportion of ticks
infected with B. bergdorferi increased as the forested area decreased.
Why would this be? In the smaller forest fragments,
many potential host species disappeared. One
species, however, whose numbers conspicuously
explode as forest area decreases is the white-footed
mouse. White-footed mice, as Dr. Ostfeld had
already shown, are incredibly efficient at infecting
ticks with Lyme disease.
What does this mean for human health? Simply put,
biodiversity protects us from Lyme disease. If you go
hiking, say, in the White Mountains of New
Hampshire, and you get bitten by a blacklegged tick
nymph, you know that tick had a wide variety of
species from which it could have taken its larval
meal, and most of those wouldn’t be likely to infect it
with the Lyme disease bacterium. On the other
hand, if you’re out on a small plot of forested land in
your suburban hometown - especially if it’s smaller than about five acres - that nymph
that bit you most likely got its last meal from a white-footed mouse, and most likely did
contract the bacterium during that meal. So your chances of contracting Lyme disease
from a tick bite are much higher in the forest fragment near your house than in the
National Forest.
If those cute little white-footed mice are the problem, why not simply get rid of them?
Attempts to eradicate rodents to a level at which they can no longer transmit disease
are notoriously unsuccessful. Attempting to rid the woods of ticks is a similarly
Sisyphean task. There is another solution: let the Dilution Effect work for us by
changing the way we manage our landscape.
Dr. Ostfeld’s work has shown that the loss of biodiversity through the fragmentation of
our native forests has real health consequences. The Dilution Effect holds true for
Lyme disease and may play a role in other vector-borne diseases as well. It’s time to
3
stop thinking of biodiversity as something that would be nice to preserve, but of no
practical value. The next time a local interest in your community wants to break up an
existing parcel of forest into smaller pieces for the sake of development, think about
the health consequences, and think twice.
Jill Hahn, a Newton Highlands resident, is a biologist, a writer, and a mom. All three
roles contribute to her passion about environmental issues. She can be reached at
jkkhahn@comcast.net.
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Wednesday, March 1, 2006
Learning Lessons From the Wind
Book Review by Eric J. Olson, PhD/ Special To The Tab
Book Review
Divine Wind, The Science and History of Hurricanes, by Kerry Emanuel, copyright 2005, Osford University Press.
If there is one must-learn phrase in Kerry Emanuel’s magnificent book it is this: hurricane amnesia. This is not what victims of hurricanes suffer after being struck by flying debris, this is the more widespread drift and denial that our seacoast culture slips into soon after the storm surge has receded and the insurance adjusters have written their reports. We stand witness to the tragedy of New Orleans--for now. We point fingers at the government--for now. We speculate on the role of global warming in all this, as if insanely powerful hurricanes were some new phenomenon on the scene. All of this diverts our attention from the real tough question, which is what should New Orleans become? And what about Florida, that vast low-lying peninsula with one of the higher growth rates of any state in the US? Do we really want to put so many families and dreams and treasure in harm’s way over and over again? This is the essence of hurricane amnesia: when a nation has such a profound attachment to place and growth and warm sandy beaches that we must forget just so we can move on. Addicts have their relatives as enablers, and we have…Uncle Sam’s flood insurance program?
Thankfully, Kerry Emanuel has written an antidote to hurricane amnesia, and in spite of his recent fame as herald of global warming (more on that below), his book also serves as a rebuttal to the notion that Katrina is retribution for the fact we’ve heated up the globe. What we get from Divine Wind is a very different image of these storms – one that we could relish if we would just pull our cities back from our subtropical coasts and watch the sea and the sun and swirling tropical air perform their ancient dance. People travel the world over to see a full eclipse of the sun or improve their look at a passing comet, why not be spectators (via satellite and pilotless planes) of the hurricane?
Here’s a pity of our modern age: we so dread these mighty winds we can’t enjoy them more. Dr. Emanuel shows the way, he is a storm-meister, a wind fanatic, a reveler in the power and the glory and the beauty of the hurricane. Read him -- you will be won over. Fond of literature? Interspersed throughout are poems, ballads, excerpts from The Tempest, snippets of great storm prose. Enjoy paintings? He has tracked down the world’s best storm-wracked work and here they are, rendered in superb color. Relish a good disaster tale? Every third or so chapter tells the story of one of the truly Great Storms of the past several centuries. Or perhaps you’re an engineer, or appreciate fine science writing? Dr. Emanuel the MIT professor patiently explains in words, with just a touch of algebra, how a hurricane is the closest thing nature offers to the ideal heat engine first described by Carnot. He even turns chaos theory into a human-interest story by telling the tale of its serendipitous discovery.
So great hurricanes have always been with us, and by building in their path we’re just asking for trouble. But there is something new, so new it’s scarcely mentioned in the book: humans are decisively fanning the flames that feed these storms. Dr. Emanuel was launched to fame this year on the basis of his August report in the prestigious journal Nature showing that hurricane intensity and duration are both increasing, in lock step with the warming of the oceans. Coming out just two weeks before Katrina, the report naturally led to a media surge on his office throughout the fall. That was when I first heard of him, interviewed on NPR, then again this January profiled in the NY Times. Sadly, the splendor of his book is lost in the intense focus on the conclusions of his Nature paper. But denial about climate change is perhaps even deeper than denial about hurricanes. Just maybe Kerry Emanuel will help us come to terms with both. We need more centrist scientists to come forward, now that the data are in. Here, listen: “There is no doubt that in the last 20 years, the earth has been warming up. And it's warming up much too fast to ascribe to any natural process we know about”. (Kerry Emanuel, NY Times, 10 January, 2006).
Hurricanes have indeed always been with us, they have always been born from hot tropical seas, and they have often slammed into land. But thanks to Dr. Emanuel we can all learn more about their savage beauty. And now he has shown us there is something new about them, that hurricane power in the Atlantic has more than doubled in the past 30 years. He and his colleagues are still working out how things could have gotten so much worse so fast, but Dr. Emanuel regretfully concludes that we humans are partly to blame. We warmed the seas, and that has changed the hurricane. Let’s not forget.
Eric Olson, PhD, Adjunct Professor of Ecology in the Sustainable International Development Program at the Heller School, Brandeis University, is Chair of the Energy Committee of the Green Decade Coalition.
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Keeping stormwater out of the Charles
By Anna Eleria / Special To The Tab
Stormwater pollution, also referred to as non-point source pollution, is one of the most significant sources of pollution of the Charles River today. CRWA is taking the lead in reducing it with a new volunteer program called the Charles River “Find It and Fix It”
Stormwater Program.<!--[if gte vml 1]>
Dave Kaplan, CRWA scientist, doing a Charles River shoreline survey in Newton |
For the next two and a half years with funding from the Massachusetts Environmental Trust, the “Find It and Fix It” Program will recruit and train volunteers to assist in inspecting the river through visual surveying and water quality monitoring in order to identify areas in need of repair. Their reports will direct CRWA scientists to areas with pressing problems and help pinpoint the areas needing further study or initiate immediate calls for action so that municipalities and landowners can fix the problems.CRWA volunteers from Newton and other watershed communities will be conducting “shoreline surveys” or visual monitoring along a 45-mile river corridor from Farm Road in Sherborn to New Charles River Dam in Boston. This spring, river surveyors will assess the river’
s baseline physical conditions and identify current or potential problems in the river, along its banks, and within the riverfront area. Volunteers will survey by canoeing or walking a half to two-mile stretch of river looking for areas of environmental degradation, erosion, and non-point source pollution. They will note the characteristics of the water, such as color, odor, and flow, in-stream and shoreline vegetation, nearby land use, and fisheries and wildlife habitat conditions. They will photograph their survey area, and they will map and characterize stormwater pipes discharging to the river.Finding every source of pollution is a big job. The visual survey information will provide the basis for CRWA’
s next steps in dealing with stormwater pollution. After compiling and reviewing this essential baseline data of river conditions, our staff will identify and prioritize the areas of most concern and determine the next steps for addressing problem areas, which may include water quality monitoring by CRWA.The water quality monitoring will allow us to focus on wet weather problems and specific sources of pollution, including stormwater pipes and other source-specific sampling locations areas, using a new set of ears, noses and eyes to pinpoint problems. Pollutants of most concern in the urbanized Charles River watershed include- but are not limited to- bacteria and viruses from combined sewage, waterfowl waste and pet waste, sediment and sand from winter de-icing applications and erosion, gasoline and oil and grease from vehicles, fuel dispensing stations and vehicle maintenance stations, and nutrients, such as nitrogen and phosphorus, from fertilizers, detergents and wastewater.
The ‘fix it’
step of the program involves sharing the results of our shoreline survey and water quality monitoring work with municipalities and other responsible parties and working closely with them to develop specific remediation measures, such as removing illicit connections to stormwater pipes, reducing use of pollutant products or equipment that generate pollutants, implementing stormwater best management practices, educating the public about stormwater impacts to the river and recommending measures to reduce them.CRWA’
s extensive monitoring efforts, including the volunteer monthly monitoring program, habitat assessments and fish studies, have shown that stormwater pollution causes degradation of water quality, wildlife and fisheries habitat, recreational uses and aesthetic beauty. With help from a network of more than 70 volunteers, we monitor the health of the river on a monthly basis at 37 sites along the 80-mile long river.Our data indicate that the river’
s water quality is generally very good over its entire length when no rain falls prior to sampling. However, during and after a rain event, water quality conditions in the river degrade and the river violates the state bacterial standards for swimming and boating. The problem is acute in Newton and other middle and lower watershed communities where urbanization and development invariably mean more impervious surfaces (i.e., buildings, streets, parking lots, driveways, etc.). This causes rainwater to flow over paved surfaces, instead of recharging into the ground, picking up manmade pollutants before flowing into storm drains that discharge into the Charles River and other bodies of water.“The Find It and Fix It”
program will get us one step closer to achieving our goal of a swimmable-fishable river.Prospective volunteers should contact Pallavi Mande pmande@crwa.org, (781) 788-0007 x 232 or see www.charlesriver.org/projects/METwMyRWA/METFF.html. For tips on what you can do to keep the river clean, see www.crwa.org/projects/stormwater/bleedsmallbrochure%20FINAL.pdf
Program and the Charles River Targeted Watershed Initiative ProjectsAn IPM Primer
By Ed Cunningham/ Special To The Tab
March, by mayoral proclamation, is Alternatives to Pesticides Month in Newton. It’s an opportunity for us to think about the consequences of our habit of adding unnecessary toxins to our city environment, to learn about alternatives, and to do something to reduce our use of toxins in our homes, our yards, our places of worship, and our places of business. The city has been trying to do its part. Ten years ago it became the first municipality in the state to adopt an Integrated Pest Management Policy to be followed in the maintenance of city buildings, parks, and grounds.
The term Integrated Pest Management sounds abstract and technical, and, in a sense, it is. The science of IPM is sophisticated, utilizing advances in computing, operations research, systems analysis, and modeling. But in the end it is common sense: it is safer, more effective, and more economical to “outsmart” pests with non-toxic methods than it is to apply pesticides and herbicides reflexively.
IPM is a set of practices and strategies that evolved from extensive agricultural research initiated in the early 1950s in response to pesticide misuse problems, reduced effectiveness of pesticide and herbicide treatments, and unintended consequences. Poisoning pests is not only a dangerous approach with unintended adverse affects, but long term it is less effective than IPM strategies.
The genesis of IPM is long and interesting. For at least 5000 years, a mixture of cultural, biological, and chemical methods have been used in agriculture to control crop-destroying pests. Cultural methods include the rotation of crops and manipulation of the dates when planting is done. Biological methods include using predatory ants to control caterpillars and beetles, as the Chinese did as early as 300 AD. Chemical intervention can be traced back to 2500 BC, when the Sumerians used sulphur compounds to control insects and mites. Late in the nineteenth century the use of inorganic chemicals emerged as the most popular means of pest control. By the 1890s it was found that lead arsenate provided very effective insect control, by 1930 synthetic organic compounds began being used for plant pathogen control, and in 1939 the pesticide properties of DDT were recognized. Based on the insecticidal properties of DDT and benezene hexachloride, the early 1940s were seen as the dawn of a new era of blissful insect control in agriculture, horticulture, and public health.
The first report of resistance to DDT was published in 1946, followed in the 50s and 60s by evidence of widespread pest resistance to DDT and other pesticides. Against this backdrop that systems analysis was first applied to efforts to control crop pests. Economic entomologists and agricultural economists weighed the cost of chemical treatment against the cost of crop loss. Chemicals were increasingly perceived as being expensive and ineffective, and alternative methods of control began to emerge under the moniker “integrated control.” In 1959 a group of entomologists from UC Berkley and UC Riverside published a landmark paper which documented pest resistance to pesticides, the destruction of natural enemies, the resurgence of treated species, the appearance of new pests, as well as health hazards resulting from toxic residues and the misuse of chemicals. By 1967 “integrated control” had broadened to encompass not only biological and chemical control, but also climatic factors, cultural control, plant growth analysis, and modeling. UC Berkley entomologists RF Smith and R van der Bosch introduced the term “Integrated Pest Management” to reflect the broadened scope of the science. Two years later the US National Academy of Sciences formalized the term, and within a few more years BS, MS, and PhD degrees were offered in the subject.
In the 1980s the principles and practices which had been developed for agricultural and forestry applications began to be used in urban sites such as schools, parks, hospitals, and nursing homes. The list of what was categorized as pests had grown to include rats, mice, squirrels, raccoons, cockroaches, wasps, yellow jackets, mosquitoes, lice, bed bugs, bats, moths, fleas, flies, birds, ants, termites, grubs, crabgrass, poison ivy--any living thing which causes a problem when it shows up where we don’t want it to be.
IPM deals with pests by identifying the problem pest and then formulating the best plan for removing the problem. Techniques include regular cleaning, eliminating access, controlling the temperature of the environment, removing water sources, ensuring that food is properly stored, and routine monitoring. EPA and USDA (Department of Agriculture) websites provide copious information on IPM symposiums, grants, and newsletters, as well as a Pest Management Strategic Plans database, an IPM Expertise database, and links to topics such as “Current PM Research” and “Information on pesticide use.” When necessary, careful and judicious chemical treatments are part of the IPM program, but they are only used when natural mortality agents are inadequate and the pesticides used allow natural enemies of the target pest to survive treatment.
Look for an article next month on Newton’s IPM policy, the work that has been done over the past ten years, and the work which remains.
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Don’t Poison Your Children and Pets
By Gilbert Woolley/ Special To The Tab
This is the time of year when the poison salesmen are at their most active. They want to sign you up to have your lawn regularly sprayed with a liquid that contains synthetic fertilizers and also chemical poisons dangerous to children and pets. Of course these chemicals are also harmful to adults, but children and pets typically come into more and closer contact with a lawn, and children are more sensitive to small amounts of poisons. The poisons are also tracked into the home on footwear and by pets, so that a baby playing on the carpet can come in contact with them.
The lawn care industry warns you to keep off the lawn until the grass is dry and for 24 hours after application. However, when the lawn is watered either by rain or sprinkler the dry ingredients become liquid again. Furthermore, if the ingredients are "safe" after 24 hours, then presumably they are also ineffective against insects.
The non-fertilizer ingredients of lawn care products are designed to kill insects and "undesirable" broad-leaved plants, such as dandelions. As some of the same "building blocks" of life are present in humans, mammals, insects and even plants, it is a good conservative assumption that any chemical harmful to one form of life is likely to be harmful to other forms, including pets and humans and, most critically, to humans still in the womb. Also, when you kill insect predators that eat the undesirable insects and the birds that eat the insects, you must then rely exclusively on chemicals to keep undesirable insects in check.
Half of the 32 pesticides typically used by lawn care providers are recognized as likely or potential carcinogens, and there are many documented cases of children and animals becoming ill after coming into contact with treated lawns. It has been claimed, although not yet statistically validated, that women living in suburban homes with lawns subjected to "lawn care "have a higher rate of breast cancer and perhaps other cancers.
In the United States more than seventy million pounds of pesticides and herbicides are sprayed on lawns, trees and shrubs each year, and much of this finds its way into groundwater, rivers and streams and drinking water. Lawn care products are a major source of chemical pollution in the US, but the use of these products is simply not necessary. Organic treatments are available which do not poison your lawn or the environment, and there are many contractors who apply them, utilizing "Integrated Pest Management" (IPM). An article describing how IPM is being implemented by the City of Newton can be found in this month’s Environment page.
How important is it to have a "perfect lawn" and does it justify the dangers to yourself, children and pets? My lawn has never been treated with pesticides or herbicides. It's not "perfect"; there are small patches of clover, but no dandelions. The secret is that every morning I look for dandelion flowers, which are not hard to see. When I am in a hurry, I just pull off the flowers and put them in the trash. If I have time, I uproot the plant with a small two-pronged tool. At first, when there were a lot of dandelions, this required some time and effort but now, one or two dandelions a day is the most I see. If you stop them seeding they cannot reproduce. My neighbor has dandelions, but the flying seeds rarely travel very far. Sometimes I deflower my neighbor's dandelions that are near my driveway.
If you want to have a beautiful lawn and don't want to use poisons, the first thing to do is to make sure that you have sufficient depth of healthy soil to support a healthy lawn. The builder of my house had dumped debris on the garden and covered it with a couple of inches of soil. I replaced this muck with six inches of topsoil and compost, and seeded it. With a sufficient depth of healthy soil you need to water much less. In the summer of 2005 I did not have to water the lawn even once.
Toxics Action Center, www.toxicsaction.org, is leading the campaign in New England to stop the use of possible carcinogens in lawn care treatment.
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Wednesday, February 8, 2006
CRWA creates a water budget
By Nigel Pickering/ Special To The Tab
Charles River Watershed Association is finding a way to meet human water demands while preserving water resources.
CRWA was selected to perform a statewide water budget analysis for the Executive Office of Environmental Affairs for 351 towns in Massachusetts. Our ground-breaking work in water budgeting began in the Charles River watershed, but is applicable in other watersheds as well. A water budget, comparable to balancing a checkbook, accounts for the amount of water that enters or leaves a watershed while quantifying the human impact on streamflow. This project, which commenced in November 2005 and will continue until June 2007, dovetails with CRWA’s flow trading efforts. Statewide maps of streamflow stress will aid in prioritizing restoration efforts and could form the basis for initiating a trading program using water banking.
For several years CRWA scientists have calculated water use patterns for all the months and all sub-watersheds ranging in size from one to five square miles. This water budget approach includes water lost from well withdrawals, transfers via water supply and wastewater pipes, and evaporation from irrigation. Also accounted for is reduced recharge from impervious surfaces (roads, parking lots, buildings) as well as flows returned to the ground from septic systems. CRWA scientists compare these water losses against data on natural streamflow in each sub-watershed to determine the level of human impact on rivers and streams. CRWA maps these results, which graphically depict river flow variations from month-to-month and the magnitude and timing of the human impact on all the sub-watersheds.
CRWA applied this specialized methodology to the Town of Blackstone to help prioritize recharge sites since the Blackstone River sub-watershed is impacted by water withdrawals, a large amount of impervious area, and wastewater losses. The town's water budget calculation identified the Lower Mill River and the Quick River as the most stressed sub-watersheds in the town, primarily because the public water wells are in, or near, their sub-watersheds. The impacts of impervious surfaces and sewering were greatest in the spring since high groundwater levels aid infiltration into sewer pipes, and runoff from impervious surfaces is not absorbed by adjacent soil. The impacts of pumping and irrigation peak in the summer. Streamflow impacts were greater in the summer when streamflows are naturally low. But with more development there will be more withdrawals, irrigation losses, impervious areas, and sewered areas, which will further reduce streamflows in the town.
Newton is different from Blackstone in a number of ways. Newton does not have any public water supply wells so there is no direct local impact in any sub-basin from a public water withdrawal well. There are a number of small golf course wells but their cumulative withdrawal volume is small. The impact of the evaporation losses from irrigated lawns is likely to be somewhat larger because, even though both communities have similar summer-to-winter ratios of water use, there are many more residential lots in Newton. Newton is on the MWRA water supply and sewer system so more water leaves as wastewater than is supplied. This apparent anomaly is because groundwater and stormwater leak into the sewer system and augment the outgoing wastewater flow. The net amount of water lost could be fairly large because of Newton's large population. Newton is also more highly paved than Blackstone so more recharge is blocked from entering the groundwater.
In summary, most of Newton is likely to have a negative water budget or a net deficit of water, thus contributing to lower streamflows during the dry periods. More exact analysis of Newton's water budget will be performed by CRWA in the next year under EOEA's new Statewide Water Budgets Analysis program.
Wednesday, February 1, 2006
Planting trees in Senegal: more than meets the eye
By John Leary/ Special To The Tab
Confronting the Sahara desert, a mere 150 miles to the north and moving steadily southward, the farmers of Kaffrine in central Senegal are facing an environmental disaster.
The Wolof people have unknowingly punished their soils with over a century of uninterrupted peanut farming. The annual harvest, which entails ripping peanuts out of the ground, leaves farmlands exposed to the intense sun and harsh winds that last the long dry season. The need for fuelwood and construction materials has depleted local forests. The Wolof are desperate for new ideas to deal with irregular rainfall, locust attacks, and the encroaching desert. For many, food security is only a dream. The baobab, tamarind, and bush mangoes that dot the horizon are all that remain of a once thriving forest, and even native Acacia trees are struggling to regenerate.
Trees for the Future's International Program Manager John Leary explains multipurpose windbreaks to Senagalese farmers.
These local environmental catastrophes on the tip of West Africa reflect global trends that affect all of us. Clearing forests releases massive amounts of greenhouse gases into the atmosphere, leading to alterations of planetary weather patterns and reducing the planet’
s capacity to sequester the greenhouse gases emitted from industries. As a result, every country is facing climate extremes, such as droughts, floods, melting glaciers, and hurricanes.Fortunately, local people are coming to understand that some of the solutions to these profound problems often lie within the collective wisdom of their own communities - in agricultural practices that have been ignored for decades.
The initial response of desperate farmers has often been to ask international development organizations to construct water pumps. In fact, access to fresh water often quickly creates a boom in vegetable and animal production. However, pumps have been only a short-term solution. What at first appeared to be a springboard to sustainable development has proven to be the Trojan Horse of the African Sahel.
It is a tragic, but common, scenario. Herds of animals concentrate at the water sources, trampling stressed soils and eating all that remains of local vegetation. New gardening industries further deplete the remaining forest resources as communities cut trees to build wooden fences in order to protect precious gardens.
At the request of village leaders and local forestry officials I began working with these Senegalese farmers in 2001 while serving as an agroforestry extension agent in the Peace Corps. They were ready to listen to anybody with a workable plan. To develop a plan that would accommodate their needs, expectations and capabilities, I knew I needed to listen carefully to what these traditional people had to say.
Agroforestry is a complex systems approach, and it takes a lot of listening to understand the needs of local agricultural systems and to ensure that a tree-planting program will meet those needs. Planting trees is the first line of defense, but it is not an end in itself- it is a preventive strategy to address many environmental, social, and economic problems simultaneously.
For that first year, I mostly listened. I learned that the Wolof people are tired of working - literally and figuratively - for peanuts. More and more, it is taking far too long to produce far too little. Production keeps falling. Soils have lost strength, and the scant remaining topsoil is badly eroded by fierce winds in the dry season. Fertilizers are expensive, and farmers get only one payday per year, in November, after peanuts have been processed. The rest of the year is a painful waiting game. Animals have nothing to eat in the dry season after all grasses have been cut or burned, and women become exhausted from walking miles to collect wood for fuel. As I listened to their stories, it became clear that these farmers actually knew the solution to their problems, and they just needed an outside catalyst.
The farmers told me that first they needed to protect their fields from animals and wind erosion. They told me they needed sources of animal forage, organic matter, and wood for fuel. They said they needed to diversify the types of crops and the timing of production. My role was to bring in outside knowledge and experiences to help communities utilize untapped resources. My solution was windbreaks - double rows of trees that protect fields and produce great quantities of useful products.
The reason these communities had not established multipurpose windbreaks decades ago was simply that no one had ever seen or heard of windbreaks. When the French colonized Senegal, they taught farmers how to use every square inch of their land to produce peanuts- techniques that became the so-called “traditional”
farming methods. But long before the French arrived, Senegalese were experts at integrating millet production in pockets of brush and forests, leaving environments intact to regenerate and serve as natural windbreaks, while keeping available a supply of native fruit and nut trees. The deeper traditional knowledge inherent in this system had been lost when lands were cleared to expand peanut production.The first year, I worked with a few farmers to surround their field with thick hedges of seedlings. We planted thorny trees on the outside to keep animals out, and we planted fast-growing trees on the inside to establish a tall windbreak. Everyone was surprised by the rapid rate of growth of these species- many grew more than 20 feet in 16 months, starting from seed! I had selected trees that quickly grow back after branches are cut, trees whose leaves drop lots of nitrogen into the starved soils and trees and shrubs that produce beans, fruits and high-protein animal forage (leaves and seed pods).
Farmers in Kaffrine have seen that the solution works. What started with three pilot farmers has expanded into 25 communities and is growing at a rate of 15 villages every year. Families have changed the way they farm, collect firewood, improve soil, feed animals and protect crops. These proud local people, with some encouragement and agroforestry knowledge from an outsider, were able to generate a local solution to a profound environmental problem.
There is much more work to do, and funding is often inadequate, although these programs are not expensive. The global community has a stake in ensuring food security for communities experiencing more droughts due to climate change, but the programs have ripple effects far beyond those communities.
Halting the erosion of the Sahara has direct benefits for people in the Western hemisphere who suffer health problems from the increasing amounts of airborne dust being carried across the Atlantic by trade winds. We live in a profoundly interconnected world, and in the long run, there is no place to hide from the serious consequences of environmental degradation anywhere on the planet.
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Education
‘Blood and Oil’ author speaks
By John Bliss/ Special To The Tab
The first of the Green Decade's 2006 Environmental Speakers, Michael Klare, Five College Professor of Peace and World Security Studies, gave a talk entitled, “Global Petro-Politics: The US, China and the Struggle Over the World's Oil,” on Monday, January 23. His main message was that the world is entering a permanent energy crisis that dwarfs the temporary shortages of the 1970's caused by the Middle Eastern oil embargoes.
Speaking to a large audience at the Newton Library, Klare pointed out that all nations are affected by high oil prices, currently approaching $70/barrel, and that no sufficiently large new oil sources are available to relieve the crisis over the next twenty-five years. He was similarly pessimistic about the prospects for new gas supplies. He noted that the U.S. Department of Energy's Energy Information Agency (EIA) had raised last year's estimate of baseline oil prices out to 2025 from $35/barrel to $60/barrel.Massive new demands for energy are coming from China, India, and many other developing countries. Klare predicted intensified competition among nations to secure the existing fossil fuel sources for themselves, which will greatly increase the chances for armed conflicts. He said that war with Iran is now more likely than not.
Klare stated that in order to satisfy the EIA's fifty-seven percent projected increase in world demand for oil and gas over the next twenty-five years, Middle Eastern output would have to triple, the Gulf of Mexico would have to remain free of large hurricanes, and nations such as Russia, Kazakhstan and Nigeria would need to remain politically stable. He noted that the problem of supply is exacerbated by the decline in oil production in Alaska and the North Sea.
Klare described the “securitization” of oil supplies by the United States over the past twenty-five years and by China more recently. He noted that the U.S. military is our nation's largest single oil consumer and the primary reason that the U.S. is involved in protecting diverse sources of supply around the world. The U.S. has intervened in Latin America and the Middle East numerous times to protect the world oil markets. China is now seeking to form alliances with Nigeria, Sudan and countries around the Caspian Sea to secure new oil sources, and this, too, raises the risk of armed conflict.
In a positive observation, Klare characterized the high baseline price of oil as “revolutionary” and believes it will stimulate investment in alternative sources of energy in ways not seen before. Although he is concerned about the environmental consequences of increased use of traditional fossil fuels, he sees only a limited role for certain alternative sources, such as the Canadian “tar sands,” and coal gasification, or “clean coal.” He noted that extracting such fuels often has negative environmental impact or requires too much energy.
Following the talk, Klare answered many questions about energy supply, international competition and conflict, and alternative energy sources and then he signed copies of his latest book, “Blood and Oil,” which were available for sale.
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Economics
The importance of oysters
Oysters have been a popular food since ancient times. Roman emperors paid for them by their weight in gold. The Romans were so enthusiastic about these marvelous mollusks that they marched thousands of slaves through rugged terrain all the way to the English Channel to gather them. While oysters have had a reputation as a delicacy for many centuries, we have only more recently begun to appreciate their environmental benefits. Scientific research has shown that oysters are voracious filter feeders. They consume large quantities of algae and excess nutrients - up to 5 liters per hour. They play a major role in maintaining the ecological balance in the waters where they grow.
Take the Chesapeake Bay, for example. Today, the water is often turbid, carrying large amounts of sediment and phytoplankton (microscopic organisms), which limits the biodiversity of the bay. However, if we go back approximately 40 years, <!--[if gte vml 1]>
NNHS Biology students Alissa Becker, left, Peter Sun and Joy Huang, right, at Whole Foods Market with their subject. |
we know that nature provided 3-4 million bushels of oysters annually in the bay, which was in great shape ecologically. These oysters filtered all of the bay’s water in a mere 4 to 5 days. During this filtering process the oysters use their cilia to strain out microscopic plants and to wrap whatever they cannot digest in mucus, which they then transport to the mouth. The mouth then does the job of breaking down the material, which moves to the stomach and is eventually expelled as feces or pseudofeces (material excreted, but not through the gut) that contribute to the sediment of the bay. Oysters consume phytoplankton so rapidly that several large oysters can clear an aquarium filled with green water within hours. When oysters strain out microscopic plants in the bay, they create room for other organisms to survive, thus maintaining the ecological balance that fosters species diversity in the bay.Sadly, the ecology of Chesapeake Bay is now very unhealthy. Oysters are nearly absent from the bay. They have been reduced to one percent of their population of 40 years ago. This is because enormous quantities of nitrogen and phosphorus (over 300 million pounds) are deposited in Chesapeake Bay each year in the form of man-made fertilizers. These provide a tremendous source of nutrients for phytoplankton and algae. When these phytoplankton and algae are overabundant they gather to form large green masses that block the light that would normally filter to the bottom and allow healthy aquatic vegetation like seaweed and ell grass to grow. The excessive phytoplankton absorbs enormous amounts of oxygen very rapidly in a given location, causing anoxia, which means that no oxygen is left to circulate in the water. The result is devastating; it kills off many animals that require oxygen to live. During the summer, when the temperatures are high and there is little vertical mixing of water in the bay, the warmer water remains afloat because it becomes less dense, while the cooler, denser water remains at the bottom. The water at the bottom can be anoxic for many weeks. This destroys many or even most of the living organisms, such as fish, leaving acres of the bay’
s bottom barren.How did such a healthy bay change so dramatically in just 40 years? There are many answers to this question, but they all boil down to this: humans have been over-harvesting a most precious natural resource. There is historical evidence that the over-harvesting of Chesapeake Bay goes back 140 years, to about 1865. Oyster harvest dropped precipitously between 1890 and 1905; even so, 12-15 million bushels of oysters were still harvested during that time period. Since 1905, the oyster harvest has declined from 5 million bushels annually to a meager 100,000 bushels in 1993. There is clear evidence that it is the drastic decline in oysters that is responsible for the drastic decline in the water quality of Chesapeake Bay.
Fortunately local governments have recognized the nature and the severity of the problem. Laws have been passed to limit the over-harvesting of oysters. For example, the 1927 10 Percent Shell Tax Law required oyster processors to make 10 percent of their shucked shell available for state use in planting, a method to create new oyster beds. The 1953 55 Percent Shell Tax, increasing the tax on oyster processors by 50 percent, was passed to slow the market demand for oysters. The 1972 Moratorium on New Leases suspended awards of new leases of oyster grounds so that the over-harvested oyster grounds could recover. Although these steps taken by governments were inadequate, they were milestones that acknowledged past mistakes and attempted to rectify them. Such laws, when combined with efforts to raise public awareness of the problem, are ways to help bring back the oysters that are so essential to the heath of the environment.
Oysters are much more than a human delicacy. They perform amazing environmental services, not only in Chesapeake Bay but also in many coastal areas all over the world. We humans should do whatever we can to preserve this delicate and delectable creature that quietly works environmental wonders.
s Biology class.
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Oceans
Cleaner cleaners in the home
By Jill Hahn/ Special To The Tab
The eye-watering smell of chlorine. The tang of ammonia. It’s great to come home to a clean house. Breathe deep. Or maybe you’d better not.
Cleaning products are among the most hazardous chemicals in your home. And because the chemicals found in cleaners are not as easily dispersed indoors as outdoors, a 5-year EPA study found concentrations of 20 toxic compounds to be as much as 200 times higher inside homes and offices than outdoors.
Then there’s the environmental impact.
Take chlorine bleach, that ever-popular cleaning product. There’s a reason why bleach is great at killing mold and bacteria: it’s toxic. Its fumes are a respiratory irritant. And when bleach, also known as sodium hypochlorite, runs down the drain, it can react with other chemicals to form toxic or carcinogenic chlorinated organic compounds, including chlorofluorocarbons which damage Earth’s ozone layer.
Sodium hypochlorite is just one of a buffet of toxic chemicals you bring into your home with your cleaning supplies. Glance at a few Material Safety Data Sheets that the Occupational Health and Safety Administration requires companies to publish: Formula 409 Cleaner Degreaser: “Reports have associated [exposure to ethylene glycol monobutyl ether with] blood and bone marrow damage...” Lysol Brand Basin Tub & Tile Cleaner:”This product contains [diethylene glycol monobutyl ether] which... has been reported to cause liver, kidney, spleen, thymus and blood effects in laboratory animals when exposed to high levels...” Parsons Ammonia All Purpose Cleaner: “Mild inhalation of ammonia vapors may cause irritation of the nose and throat with coughing and sneezing. A more severe exposure may cause ... labored breathing, and pulmonary edema.”
Not good.
But if you don’t snort the ammonia, or bathe in the Lysol, are these chemicals really a problem? Research shows that they can be. Volatile organic compounds (VOCs), such as xylene, ketones, and aldehydes, are found in many aerosol products and air fresheners. In one study, babies less than six months old in homes where air fresheners were used on most days had 30 percent more ear infections than those exposed less than once a week.
So what is the conscientious homemaker to do? The first thing you need to do is retrain your nose. Your house doesn’t have to smell like a chemistry experiment in order to be clean enough. Before the golden age of synthetic chemicals arrived in the mid-twentieth century, people didn’t have access to such miracles of modern science as Fantastik with Scrubbing Bubbles. Instead, they used a handful of simple yet effective substances, such as soap (not detergent, which is usually petroleum-based), vinegar, baking soda, borax, alcohol, and cornstarch to deodorize, polish, disinfect, scrub, remove stains, and wash clothes. These ingredients are still available, and still effective.
And maybe we need to redefine “clean enough.” We’ve become germ-phobic, with consequences that, paradoxically, may be endangering our health. The Centers for Disease Control have shown that antibacterials such as triclosan and benzalkonium chloride, which have proliferated in household products recently, are resulting in an increase in bacteria resistant not only to those antibacterials but to antibiotics such as penicillins and cephalosporins as well. This is particularly troubling considering that, according to Stuart B. Levy of Tufts University School of Medicine, no current data demonstrate any health benefits from having antibacterial-containing cleansers in a healthy household.
In addition, evidence is mounting that people who have been raised in an environment overly protective against microorganisms may suffer from an increased frequency of allergies, asthma, and eczema.
So when you’re buying your next batch of household cleaners, what should you look out for?
First, avoid products labeled “antibacterial.” For those instances when you really need to disinfect (you’ve just spilled icky chicken water all over your countertop and you’re worried about salmonella), bleach, alcohol, or peroxide will kill those germs without selecting for resistant bacteria.
Don’t buy products with bleach added. If you want chlorine bleach in the house, buy a small bottle and use it sparingly, only when something less toxic won’t work. Otherwise, look for oxygen-based bleach.
Examine labels, and if a product has a VOC concentration higher than 10% of its weight, put it back.
Choose products with a phosphates concentration of 0.5% or less (phosphates aren’t a threat to your immediate health, but they wreak havoc on the health of the waterways near your house). Even if you alternate use of a low-phosphate product with use of a conventional cleaner, it’s an improvement.
Which is a rule to live by. Small steps count. If you succeed in reducing, rather than eliminating, your dependence on toxic chemicals in the home, you’re still doing yourself, your family, and the environment a big favor. And who knows, someday you may find that the fresh, orangey smell of citrus oil means a clean house, and the smell of chlorine only reminds you of a swimming pool.
Jill Hahn, a Newton Highlands resident, is a biologist, a writer, and a mom. All three roles contribute to her interest in environmental issues. She can be reached at jkkhahn@comcast.net. This article is archived at www.greendecade.org/tabarchive.asp
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Waste
Winter’s assault of rock salt
By Bruce Wenning/ Special To The Tab
During the winter our environment is inundated with road salt. Millions of tons of de-icing salt, commonly called rock salt (sodium chloride) is applied to roads, parking lots, sidewalks, driveways, and stairs to melt ice or prevent ice formation. This is done to reduce the hazard of pedestrian slips and falls and vehicle accidents. However, it is not effective below 20 °F.
However, rock salt applied for our safety has several non-target pathways in the environment: (1) it seeps into pavement surfaces and creates a reservoir of salt for later transport for contamination, (2) it is splashed to roadside soil and vegetation by vehicles where it is concentrated in plowed and shoveled snow piles (3) it is washed away by surface runoff into soil, ground water, rivers, lakes, ponds, and streams (4) it leaches through soil into the plant root zone (5) it becomes air-borne into our atmosphere and settles on vegetation (6) it gets onto vehicles and roadway structures contributing to corrosion.
Rock salt is toxic to many perennial plant species of trees, shrubs, grasses and herbs. Salt-contaminated snow and ice eventually melt and leach into soil, killing soil microbes, which contributes to soil compaction.
Rock salt in soil breaks down into ions of sodium and chloride. The chloride ions are the more damaging; when taken up by plant roots in spring and summer they are transported to growing points such as buds and branch tips, killing them. Leaves show symptoms of salt damage by exhibiting brown colored leaf margins. This is where chloride ions were deposited and concentrated in the leaf tissue, creating localized cell death that resembles drought stress. Eventually entire leaves can “brown out” and die. Twigs and small branches can soon follow suit.
Vehicular traffic on salted roads releases pavement salt, making it airborne. Rock salt molecules travel in wind currents created by traffic flow and settle on roadside vegetation. This action, called salt spray, can cover trees as high as forty feet and an area as deep as 150 feet from the road, although the most noticeable plant damage is within thirty feet of the road. Contaminated soil and salt spray are the two most common ways plants get injured from road salt.
Repeated exposure to rock salt by salt sensitive deciduous trees will cause bud death and branch dieback, forcing dormant buds below the affected area to grow out in response. This recovery growth response of multiple stems with leaves is called “witches brooms” and it is diagnostic of salt exposure. It is easily observed on cherry and maple trees along heavily salted roadsides. Another sign of rock salt toxicity is summer and early fall defoliation.
Evergreen trees such as hemlocks and pines show brown-tipped needles well into summer. With annual exposure to salt spray from traffic or soil contamination, the needles turn completely brown, die and fall off. Evergreens and salt-sensitive deciduous plants are weakened by repeated exposure to rock salt, increasing their susceptibility to insects, diseases and fertility problems; this can lead to their premature death.
There are protective measures you can take to lessen the effects of rock salt damage to plants. First, switch to sand or use ice melting products that are safer for plants, pets, and the environment, such as potassium chloride or “pet safe” calcium chloride products, which are effective de-icing compounds to -15 °F and below. Although these products are a little more expensive than rock salt, they significantly reduce plant damage and environmental contamination. Second, plant salt-tolerant plants. Third, protect salt sensitive plants with burlap wraps, wooden coverings facing the road and by flushing the root zone in spring and summer with lots of water, although root zone washing is only effective with well-drained soil.
Pirone’s Tree Maintenance (7th ed.), Hartman, Pirone and Sall. ranks trees from “Very tolerant” (least sensitive) to “Intolerant” (most sensitive), as follows: Very tolerant:White oak, red oak, black cherry, and eastern red cedar. Tolerant:Yellow birch, black birch, paper birch, gray birch, black locust, and largetooth aspen. Moderately tolerant: Norway maple, red maple, shagbark hickory, hop-hornbeam, American elm, and linden. Intolerant: Sugar maple, white pine, hemlock, beech, red pine, and speckled alder.
For more information, see: www.UMassGreenInfo.org, www.extension.umn.edu, www.safnet.org.
Bruce Wenning is Horticulturist / Grounds Manager at the Massachusetts Audubon Society’s Habitat sanctuary, Belmont and serves on the Board of Directors for the Ecological Landscaping Association. www.ecolandscaping.org.
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Health and Pollution
What is ‘perc’?
By Gilbert Woolley/ Special To The Tab
You may have seen a sign in your dry cleaning store: "Perc free cleaning available" and wondered what is "perc " and why you might not want it to be used. “Perc” is short for Perchloroethylene,(C 2 Cl 4), a chlorinated solvent that goes by several other names including PCE and tetrachloroethylene and several trade names. In the forties and fifties perc replaced trichloroethylene, which had replaced carbon tetrachloride (both more hazardous than perc), and is now the solvent used by 90% of dry cleaners in the US. Perc is also widely used in industry as a degreaser. Annual usage in the US is many million of gallons of perc. Some of this undoubtedly finds its way into the groundwater and into drinking water. This cannot be good for the earth or the people living on it!
Chlorinated solvents have been shown to cause cancer in some animals and studies of workers in the US who are in daily contact with Perc vapor have found significantly higher levels of esophageal, bladder, tongue, intestinal, lung and cervical cancer. This is consistent with studies in Canada and the UK.
The US OSHA (Occupational Safety and Health Administration) warns that perc is a possible human carcinogen (04/15/05) and strictly limits exposure in the workplace. The International Agency For Research on Cancer classifies perc as a "possible human carcinogen". (1995). Perc accumulates in body fat. More immediate effects include nausea, headaches, dizzy ness and drowsiness. As a customer you wont be exposed to the same levels but it's a good idea to avoid exposure to harmful chlorinated solvents, and people who are sensitive to chemicals should beware of contact with garments cleaned by perc.
Like tobacco and alcohol, Perc is not a deadly poison, but it is harmful, and dry cleaners should be required to provide a written warning to customers, just as makers of tobacco products and alcoholic drinks are required to do. This warning should give the “possible carcinogen" status and warn chemically sensitive users about perc.
For people who are not exposed to perc in the workplace the most likely pathway into the body is through the lungs. You must have noticed the rather unpleasant odor of newly dry cleaned garments Tests show that, even after a hundred days, 40% of the perc in the garment after cleaning is still present. When you pick up a garment from the dry cleaners you should take it out of the plastic bag and hang it outdoors or in a well-ventilated area for some days to reduce the amount of perc vapor you bring into your home. This is especially important for large, heavy items, such as "comforters" and sleeping bags, and when a number of garments are packed in one bag. People who live over, or near to a dry cleaning operation may be exposed to harmful levels of perc vapor.
NIOSH (National Institute of Safety and Health) studied methods to limit perc emissions. The study confirmed that technology is available in Europe to do so. Germany has imposed regulation to mandate use of such technology. This requires a considerable capital investment, and without similar regulation in the US there is no incentive to make this investment. Government regulations prohibit the disposal of perc or water containing perc into a sewer, but these regulations are largely self-enforced. Sewage treatment does not remove perc and treated wastewater will be discharged into rivers or the ocean. Perc has been detected in drinking water at many locations in the US.
Alternatives to perc
Google "perc alternatives" to find alternatives to perc. One "perc free" option is "wet clean", the use of detergents and water instead of perc. Google "wet clean" for more information. There are fabrics that are difficult to wet clean without shrinking and some stains that are easier to remove using perc, but many garments carrying the "dry clean only" label can be safely wet cleaned. New wet clean technology has tightly-controlled temperatures for washing and drying, which makes if possible to wet clean some articles that would be difficult to wash using conventional methods. The most complete page is by the US EPA, (labeled) PDA which gives information on wet cleaning and also lists providers of non-perc cleaning by state.
Wet cleaning eliminates many of the disposal problems of perc because the wastewater can be safely discharged into the sewer. Another advantage is that "non perc" cleaners do not have to register with the EPA.
Another "perc free" method is to launder articles in liquid CO 2 (carbon dioxide), which is non-toxic but this method is not in widespread use. The dry cleaner I use in Newton advertises "perc-free cleaning available" but his system uses oil based, not water based, cleaning fluid.
How to limit exposure to perc
· Buy as few garments as you can, which carry the "Dry Clean Only" label
· Use a "wet cleaner" The US EPA web page lists four wet cleaners in Massachusetts, including one in Newton: Corner Cleaners, 1301 Washington St, West Newton.
· Google "wet cleaners" to get more information
· Ask your dry cleaner to offer "perc-free" cleaning.
· Have garments dry-cleaned less often
· Try careful hand washing. For guidelines go to Google: "stain removal".
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