Week of 5/16/2004

Dear EarthTalk: What happens to the chemicals in drugs once they are out of our systems?

Courtney Moschetta, Huntsville, AL

Every time you swallow a pill, some of that medicine follows a circuitous path through your body, down the toilet, through the sewage treatment plant (where if is often resistant to traditional treatments) and into the nearest river or lake, where it is eventually tapped again for the public drinking water supply.

According to Christian Daughton, chief of environmental chemistry at the U.S. Environmental Protection Agency’s (EPA) National Environmental Research Laboratory in Las Vegas, new technologies now allow scientists to detect extremely low levels of prescription and over-the-counter drugs, as well as compounds found in personal care products like shampoo and sun screen, in water. In Kansas City alone, more than 40 percent of stream samples analyzed recently by the U.S. Geological Survey had detectable amounts of over-the-counter-drugs like ibuprofen and acetaminophen, antibiotics, and prescription medications for high blood pressure.

While the effects on human health of drug residues in water are not yet a serious concern, new studies show that fish and other aquatic species may be affected, says Daughton. Antibiotics make some species more resistant to pathogens, steroids can cause endocrine disruption that interferes with reproductive processes, and anti-depressants make fish tranquil and more likely to succumb to predation. Considering the large variety of pharmaceuticals on the market today, our water may have a witch’s brew of very small amounts of many different kinds of drugs.

Right now there are no EPA or Food and Drug Administration regulations in place to control levels of residual drugs in water, but some environmental groups concerned with water quality want to see drug disposal policies enacted, new sewage treatment technologies developed, and source reduction efforts on the part of pharmaceutical companies and pharmacies. Daughton envisions a day when drug companies will take responsibility for the lifecycle of their products. Instead of flushing your unused prescription drugs down the toilet, you may be able to send them back to the pharmacy or return them to the maker for proper disposal. Such programs already exist in areas of Europe and Canada.

CONTACT: EPA National Environmental Research Laboratory, Environmental Sciences Division, http://www.epa.gov/nerlesd1/chemistry/pharma/overview.htm; United States Geological Survey’s Toxic Substances Hydrology Program, http://toxics.usgs.gov/regional/emc.html.


Dear EarthTalk: I’ve heard that Singapore controls the number of cars on its roads. How does this work?

Karen Abromovich, Trumbull, CT

Nearly 42 million cars were produced worldwide in 2003. More cars, of course, mean more congestion and more air pollution. In response, a handful of regions, including Singapore, are trying to limit the number of cars on the road.

Singapore implemented a "Vehicle Quota System" in 1990. According to the Singapore Land Transport Authority, which administers the program, the number of new vehicles allowed for registration is pre-determined annually, taking into account prevailing traffic conditions and the number of vehicles already on the roads.

The vehicle quota for any given year is administered through a monthly auction of "certificates of entitlement," which are bid by prospective car owners and must be obtained before their vehicle is allowed on the road. This free market approach sets a relatively high price for a certificate; a quota premium on a car can cost as much as $16,000 in U.S. dollar equivalent. But as a result of the program and its high prices, the number of automobiles in Singapore increased just 22 percent from 1993 to 2003 (from 584,000 cars to 711,000), even though population increased 46 percent during the same time period.

Last year London began implementing a "Congestion Pricing System," which is being touted as the new international model for transportation reform, according to Walter Hook, executive director of the Institute for Transportation & Development Policy. Between the hours of 7 a.m. and 6:30 p.m. there is an extra charge to drive on certain downtown roads. Exemptions exist for taxis, emergency vehicles and other special classes of cars, including alternative energy vehicles. Traffic is monitored by camera, and violators risk fines starting at 78 pounds ($140 U.S.). The British government hopes to cut congestion downtown—where traffic speeds now average three miles an hour—and raise 130 million pounds ($230 million U.S.) per year in the process. A similar system has been in place in Trondheim, Norway for at least 10 years.

Could such systems ever work in the U.S.? Michelle Ernst, senior analyst at the Surface Transportation Policy Project, which advocates for alternative transportation choices, is doubtful, saying that Americans are too attached to their cars, and at present public transportation in many areas is not convenient. "If a system similar to Singapore’s were to be implemented in the U.S., a likely candidate would be New York City, where there is a well developed dense urban core. But that’s a long way off," says Ernst. "Mayor Bloomberg was interested, but found it politically unfeasible."

CONTACT: Singapore Land Transport Authority, +011 1800 – 2255 582, www.lta.gov.sg/; Institute for Transportation & Development Policy, (212) 629-8001, www.itdp.org; London City Hall, +011 020 7983-4000, www.london.gov.uk/mayor/congest/index.jsp; Surface Transportation Policy Project, (202) 466-2636, www.transact.org.

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