Wednesday, February 7, 2007

Burn Fat, Not Fuel!

 

Cycling 6 miles to and from work instead of driving could burn 15 to 20 lbs. of fat each year.

Pollution Facts:

·      60% of car emissions pollution occurs in the first few minutes, before pollution control devices can work effectively.

·      Approximately 40% of all car trips are less than 2 miles.  Biking (10 minutes) or walking (30 minutes) instead of driving, would keep about 15 pounds of pollutants out of the air. (World Watch Institute)

·      Motor vehicle emissions represent 31% of total carbon dioxide, 81% of carbon monoxide, and 49% of nitrogen oxides released in the U.S.

Fat Facts:

·      In the U.S. 16% of children ages 6 to 19 years are overweight.

·      In Holland 11% of children ages 7 to 11 years and 8% ages 13 to 17 years old are overweight.

·      64.5% of U.S. adults, age 20+ years old, are overweight and 30.5% are obese.

As a bicycle commuter and member of the Newton Bicycle Pedestrian Task Force, I have a strong personal interest in making Newton more "bicycle friendly".  My co-workers echo the findings of a 1995 Rodale Press survey, which found that 40% of U.S. adults said they would commute by bike if safe facilities were available.

Recently I talked with Anne C. Lusk, Ph.D., Visiting Scientist at Harvard’s School of Public Health, with 25 years of experience working with communities to create bicycle paths, including the Stowe (VT) Recreation path.  She once bicycled 1000 miles from Boston to Washington, D.C. to explore the route for the East Coast Greenway.  Dr. Lusk is writing a book, "Designing a Healthy America: Bicycle Paths, Parks, and Streets".

Dr. Lusk maintains that American communities should provide European Cycle Tracks so that cycling and walking could be part of the solution to the growing American obesity crisis.  By separating vehicular traffic from pedestrian and bicycle traffic (and from other wheeled, non-motorized traffic such as in line skating), walking and cycling become safer and, therefore, viable, options for the entire community.

By building safer cycling facilities alongside, but separate from, roads, bicyclist fatalities were reduced by 64% in Germany and by 57% in Holland between 1975 and 2001.  In the U.S. today, a bicyclist is twice as likely to be killed as a German bicyclist and over three times as likely to be killed as a Dutch bicyclist

 

Dr. Lusk maintains that American communities should provide European Cycle Tracks so that cycling and walking could be part of the solution to the growing American obesity crisis.  By separating vehicular traffic from pedestrian and bicycle traffic (and from other wheeled, non-motorized traffic such as in line skating), walking and cycling become safer and, therefore, viable, options for the entire community.

Today children no longer ride bikes or walk to school and adults spend hard-earned money on memberships to gyms they drive to where they spend scarce time exercising instead of incorporating exercise into their daily routines.  We drive everywhere and make many highly polluting short trips. Then we complain about the traffic.   Many European countries explicitly chose to create and improve mobility opportunities for children and seniors in the 1970s.  During the same time, the U.S. chose, instead, to provide more facilities for cars and trucks.

The development of bike paths does not happen spontaneously in an urbanized environment. It needs catalysts. The extremely popular Minuteman Bikeway from Cambridge to Bedford was a government project. It connects several local communities on an old railway bed that leads to a national park. In many communities, citizens have to organize at the grassroots level or local politicians have to lead the way to get things started.

In Newton, we already have a bike path along the Charles River. However, there are no safe connector paths to it, so cyclists need to ride in the street to get there, making it inaccessible to the vast majority of cyclists (children, senior citizens, occasional cyclists, those with impaired mobility) who are unable or afraid to ride on the road.

Dr. Lusk indicated that funding is available for creating cycling facilities, but that first there should be a consensus about what needs to be built, and where.  She said: "The most far reaching thing would be to build European Cycle Tracks in Newton.  You can't have a system with short sections of paths that aren't connected.  You need an interconnected system for all people, not just fearless road cyclists.  Pedestrians, vehicles and bikes should be separated."

How do we get started?  According to Dr. Lusk, “It's easy to come together for a common cause, but people need to know that they can effect change.  Even in Chicago and New York they're doing bike things.  Boston isn't doing 1/10th as much as Chicago.”

I can imagine European Style Cycle Tracks connecting Newton's Village Centers, the Charles River Bike Path, MBTA stations, schools, and on Beacon Street leading into Boston.  Please share your ideas about this with the Task Force.

Molly Schaeffer, a Chestnut Hill resident, commutes to her job as a systems consultant on an aging Bridgestone bike. She can be reached at mailto:mhschaeffer@alum.mit.edu.  

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Phthalates: Should You Be Concerned?

 

 

If you own anything that’s plastic and flexible, chances are likely that you own something containing phthalates.  Phthalates, also known as phthalate esters, were first introduced in the 1920s and are a group of compounds added to plastics to convert them from a hard to a flexible plastic.  When added to a hard plastic substance, phthalates react with the polyvinyl molecules, disrupting the rigidity of their interactions and allowing them to slide over one another more easily.  Different types of phthalates are found in products as diverse as flooring material, PVC pipes, perfumes, pesticides, children’s toys, nail polish, adhesives, cars, medical devices and caulk.  Debates in the health literature about the potential harms of phthalates are ongoing, but worth examining.  In this article, I will present some basic information on current knowledge about phthalates’effects on human health and argue that the U.S. should regulate the manufacture of phthalates.

In the body, phthalates are fat soluble, so when ingested, will tend to accumulate in areas of the body with a high fat concentration.  A National Health and Nutrition Examination survey conducted in 2003 found that most of the U.S. population had some measurable exposure to various phthalates.  In high doses, several phthalates have been shown to stimulate hormonal activity in rodent models.  One particular phthalate, DEHP, has been recognized as a testicular toxicant and an androgen disruptor, leading to malformation of male genitalia and death of testicular germ cells.  At even low exposures, another type of phthalate, DBP, has been shown to act as an endocrine disruptor and damage the reproductive system in male rats.  Some phthalates are also thought to be estrogen imitators, potentially causing infant boys to display an increase in female sexual characteristics.  In 2005, a study conducted at the University of Missouri-Columbia showed that infant boys born to mothers with high phthalates urine concentrations displayed a significant shortening of the anogenital distance (AGD), a smaller penis size, and were more likely to have non-descended testes.  The National Toxicology Program, however, has criticized this study for its use of a small sample population from a homogenous area.  Further studies are currently underway to provide more conclusive data.

Despite all this literature on the harmful effects of phthalates, research indicating the contrary – that there are no harmful effects of phthalates on human health – also exists.  A study conducted by the Children’

s National Medical Center showed no conclusive adverse physical or chemical effects in adolescent children who were exposed to phthalates as neonates.  Additionally, a study conducted in September of this year showed that high levels of DEHP phthalate caused no adverse effect on the development of sex organs in male marmosets.

Given that there is some uncertainty about the dangers of phthalates, what should we as consumers do to protect ourselves from possible adverse effects?  The European Union has already banned the use of six phthalates in the production of children’

s toys as a precautionary measure against potential harms.  The regulation of phthalates is an excellent illustration of the Precautionary Principle at work.  That is, even in the absence of definitive data concerning the harms of phthalates, those who create public policy have an obligation to take precautionary measures and ensure public safety by enacting policies that mandate safer alternatives-- unless and until phthalates are proven to be safe.

Manufacturers and lobbyists may insist that a switch from phthalates to other substances will be expensive, but these costs are often exaggerated. Even if the costs are substantial, they would diminish over time after the switchover. From a public health perspective, the public has a right to insist on safer alternatives, even if the risks of phthalates and the costs involved in restricting or banning them are controversial.  The FDA does not mandate manufacturers to investigate the risks of their products before marketing; thus, the burden of investigations falls upon scientists and public health officials –

a process that may take years to complete.  A responsible approach in the meantime would be to restrict the use of phthalates until more conclusive data is available.

For additional information on phthalate safety, see the U.S. EPA website, the Center for Food Safety and Applied Nutrition website of the FDA, the Official Journal of the European Union (with a recently published commission recommendation on risk reduction measures), and the website of the CDC.  The Phthalate Information Center (www.phthalate.org) of the American Chemistry Council provides the perspective of phthalate manufacturers.

Yi Li is a first-year student at Harvard Medical School.

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The Wonder of Green Roofs

 

The term green roof refers to a roof that is partially or completely covered with vegetation, usually with special membranes to protect the rooftop and hold the plants and growing media in place. Green roofs are a proven technology with significant potential to stabilize our climate by cleaning and cooling our air and reducing stormwater runoff.

Green roofs date back at least to 600 BC, to the Hanging Gardens of Babylon, one of the Seven Wonders of the World.  These were terraced structures that were built over arched stone beams, waterproofed with layers of reeds and tar, covered with soil and planted with trees and plants.  There are houses in the Orkney Isles of Scotland from 3600-2500 BC that appear to have had turf roofs. In Iceland, sod homes with grassy roofs were constructed hundreds of years ago. The idea spread throughout Scandinavia and other parts of Europe.  There is a green roof that was planted in 1914 in Switzerland on which an orchid (Orchis morio) thrives today that is otherwise extinct in the region, The Rockefeller Center in New York City has several green roofs that were installed in the 1930s.

Germany has been perfecting modern green roof technology since the early 1970s when the first complete green roof systems were developed and marketed.  These intensive systems require thick planting media of 8 inches or more to support a variety of plants and trees and can add upwards of 54 pounds per square foot.  In the late 1980s many green roof systems were developed for large flat roofs; these lighter and cheaper versions were designed to be self-irrigating and require minimal maintenance.  These systems are generally 3-5 inches in depth, weigh around 20-34 pounds per square foot and utilize various species of sedums, which are hardy succulent plants. 

Green roof systems can be incorporated into new construction or retrofitted onto existing buildings. 

They are usually found on commercial and public buildings, although they can be installed on smaller residential surfaces. Green roofs, unlike roof gardens, are applied as part of the roofing system and can be installed on a pitched roof. The components include the roof structure, a waterproofing membrane, a root barrier, a drainage system and/or water retention system, filter cloth to maintain the integrity of the green roof layers, a specially engineered lightweight growing medium, and plants. The cost of greening a roof starts at $11 per square foot, not including the structural analysis to determine the roof’s load capacity. 

Green roofs serve many environmental functions. They absorb carbon dioxide from the atmosphere in exchange for life-giving oxygen, they cool the air and they retain stormwater.  That means that once installed, they immediately reduce the urban heat island effect, reduce energy costs and reduce stormwater runoff. According to Prof. Brad Bass of University of Toronto, when a city installs enough green roofs to achieve a 1ÂșC drop in temperature, this will result in a 10% reduction in energy use. Green roofs also provide environmental services by creating new space for biodiversity to thrive, reducing allergens and asthma, diminishing air and noise pollution, and increasing roof longevity (which reduces the need for disposal of old roof membranes).

Nearly 10% of Germany’s building surfaces have green roofs, covering 50 square miles, and is currently adding 5 square miles of green roofs per year. North America lags far behind, with slightly more than 2 million square feet of green roofed space. Green roof installation is costly in the US, so the economic benefits are not always sufficient to motivate consumers.  Our local, state and federal governments need to provide incentives to accelerate the process.  In Toronto, the city subsidizes green roof installation by $2 per square foot. Germany offered large incentives during the initial years.  Tokyo passed a law in 2001 to require new buildings to green at least a fifth of their rooftops.  Chicago, a city with a celebrated green roof on its City Hall, has more than 200 green roofs, and is perhaps the greenest city in the US. It is now requiring developers to green all buildings that undergo city review.

When we cool our coastal cities with sufficient numbers of green roofs, we may even begin to cool our oceans by limiting freshwater runoff, and thereby slowing the rate at which coastal waters are being reduced in salinity due to human activity.  Some advocates feel that green roofs have the potential to keep the Atlantic’s thermohaline pump performing properly.

Green roofs limit greenhouse gas emissions, and therefore can help to slow global warming. The northeast corridor, from Boston to Washington, DC is contributing an enormous burden of CO2 to the atmosphere. Policymakers have an opportunity to turn our urban corridor into the Eighth Wonder of the World, a carpet of green roofs, and help preserve a livable world.

Earth Our Only Home, Inc. is a company led by three mothers committed to reversing the rate of global warming through green roof technology, www.earthouronlyhome.com

 

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