sad state of environmental health

The Sad State of Environmental Health Policy Today

The other day, Revere was discussing John Edwards's presidential

platform on cancer, and expressing disappointment that Senator Edwards

gives virtually no attention to prevention, including regulatory

approaches for reducing carcinogenic exposures and incentives for

promoting "green chemistry" in manufacturing. I checked over at

Hillary Clinton's web site, which has a bit more meat on this topic:

smoking prevention in young people, getting junk food out of schools,

and improving biomonitoring of exposure to toxic substances. However,

it's only a slight improvement over what John Edwards would provide

for us. To the credit of both of them, they appeared at Lance

Armstrong's cancer forum earlier this week (most of the Republican

candidates bailed on it).

It seems so hard for our politicians to inject the environmental

health focus into the debate over health care. Perhaps it's too

difficult for them. Too much of our economic system would have to

change. For example, in a paper published last month in Environmental

Health Perspectives, the cancer risks from organic hazardous air

pollutants were ranked for a non-occupational and non-smoking

population. The chemicals providing the largest contribution to total

estimated cancer risks in the U.S. were benzene, butadiene,

formaldehyde, dioxins and chloroform.

Mobile sources (cars and trucks) are a large part of the emissions of

benzene, butadiene and formaldehyde into the air. So, by inference, a

key strategy for reducing exposure to these substances could be to

reduce the amount that we drive, or ship stuff around by truck. The

alterations to our daily lives could range from minor, such

carpooling, greater proportion of working from home, or buying

locally, to fairly life-changing stuff, including redesigning cities

for walking and urban biking, substantially increasing the urban mass

transit infrastructure, changing patterns of employment, old

industries collapsing while new ones flourish. . . more examples are

provided here. There would be collateral benefits, too: redesigning

our built environment to be more friendly to pedestrians and

bicyclists could create a health benefit, and possibly cut into health

care costs, by increasing the amount of exercise people get (NIEHS had

a conference on this topic in 2004); in addition, reducing

vehicle-miles traveled also reduces our consumption of oil, which

promotes energy independence and begin reducing greenhouse gas

emissions, both of which pose a risk to national security. Oh, and all

of the upgrading of our infrastructure that would be needed to

accommodate fewer cars and trucks in our lives would create jobs. . .

. Stop me if all of this is making too much sense.

Chloroform occurs in drinking water as a disinfection byproduct (most

chloroform exposure occurs indoors when we use that water - either

from drinking, or inhaling chloroform that volatilizes from hot water

during showering or using a washer or dishwasher). While the

disinfection of drinking water using chemicals such as chlorine has

been a major public health success story by reducing the risk of

disease, elevated levels of disinfection byproducts may be associated

with an increased risk of bladder, rectal, and/or colon cancers and

adverse pregnancy outcomes. Many water utilities use chlorine gas for

disinfecting drinking water, and chlorine is transported around the

country in rail cars. Derailments have created hazards and caused

fatalities to communities in the past (I've blogged about one such

story in Graniteville, SC in 2005; as discussed here, further work is

needed to increase the safety of rail cars transporting hazardous

materials). However, alternatives are available for disinfection of

drinking water that can reduce the formation of disinfection

byproducts and at the same time reduce accidental releases from

derailments by limiting the amount of chlorine transported around the

country. There would need to be an investment made to fund the

retrofitting of water treatment plants - but again, you could look at

this as an opportunity for job creation.

The story is bit different for dioxins. People are exposed to dioxins

principally through the food supply, particularly by eating animal

fat, dairy products and fish. In 2003, the Institute of Medicine

published a report discussing strategies for reducing exposure to

dioxins in foods. Overall, about 34 percent of the calories in

American adults' daily diet come from fat, and one-quarter to

one-third of that is from saturated fat, which is largely animal fat.

Recommendations for reducing dioxin exposure in the diet (which, by

the way, would also reduce exposure to other lipophilic persistent

organic pollutants) include changing agricultural production methods

to interrupt the cycle of dioxins through forage, animal feed, and

food-producing animals, particularly with regard to the use of animal

fats as livestock feed. In addition, they recommend educating people

about reducing the amount of fat consumed in their diets. In general,

making people more aware of the consequences and benefits associated

with what they eat can provide health benefits beyond reducing

exposure to dioxins and persistent organic pollutants.

There are pollutants not covered in the EHP article, because they

aren't hazardous air pollutants, but that still are examples of how

attention to environmental health can have collateral economic

benefits. For example, nearly 2 billion pounds per year of bisphenol-A

are used in the production of polycarbonate plastics. Polycarbonates

are used to manufacture all types of plastic components, including

food and drink containers. There potentially are problems with using

polycarbonates in food and drink containers - bisphenol-A can leach

from them and be ingested. This makes bisphenol-A a textbook example

of an environmental toxicology and health policy problem. It's a

commercially important chemical substance. Nearly all of us are

constantly exposed to low levels of it. The mechanisms for potentially

adverse health effects are subtle and occur at low levels of exposure.

The most vulnerable populations for these effects are young children,

both during pre-natal development and in infancy. The kinds of

biological effects observed in laboratory animals with low levels of

exposure include stimulating the growth of prostate (in males) and

mammary tissues (in females), potentially increasing susceptibility to

carcinogenicity later in life; alterations in hormonol with effects

such as early onset of sexual maturation; and neurobehavioral effects.

Recently, one study provided indications that BPA might promote

insulin resistance, a risk factor for diabetes. These effects can be

observed at levels around 10-fold greater than levels of exposure in

humans, which is not a comfortable margin of safety. As yet, adverse

effects have not been observed in humans, though there hasn't been a

concerted effort made to examine human populations.

Bisphenol-A is not the only component in plastics manufacturing with

health concerns. Health effects potentially associated with

phthalates, used as plasticizers, and perfluorooctanoic acid (PFOA),

the precursor used to make Teflon, are also under scrutiny. As with

bisphenol-A, these substances are in widely used products, and we all

carry around a small body burden of them. As can be imagined, there is

a strenuous scientific debate about the presence and significance of

adverse health effects from exposure to bisphenol-A, phthalates and

PFOA, a debate which may never be satisfactorily resolved. However,

there is an opportunity to promote the research, development and

manufacturing of lower-toxicity materials for use in consumer

products, which could help to reduce the uncertainty regarding health

risks from plastics. There are many initiatives promoting "green

chemistry" (the Lowell Center for Sustainable Production and the Clean

Production Action project are resources for learning more about this

topic). However, while the chemical manufacturing industry

acknowledges the importance of green chemistry, redirecting it onto a

more sustainable path will happen faster if political pressure is

applied.

Which brings us around to what our presidential candidates have said

about cancer prevention, and more importantly, what they haven't said.

Dealing with disease burdens such as cancer is more than just fixing

health insurance and giving more money to NIH. It is taking a more

holistic view of how physical and socioeconomic factors can affect

human health. Environmental health is very much a democratic issue.

The Democratic candidates for president should be able to say more

about it than they currently are doing.

Labels: clean production, environmental health policy, sustainable