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The environmental dirty dozen >> A UN-sponsored conference in Montreal puts 12 pollutants on the global hit list by WAYNE HILTZ
All 12 are classified as Persistent Organic Pollutants (POPs), considered hazardous because of their resilience. POPs take several decades (if not longer) to break down, travel long distances through air and water currents, and enter the food chain by contaminating the fat tissues of virtually all living creatures. Exposure to the dirty dozen has been shown to have such serious consequences that UNEP has put them on an ecological hit list. "These substances travel readily across international borders, making this a global problem that requires a global solution," said UNEP executive director Klaus Topfer in a statement issued last week. Because of their persistence and their prevalence, there's little that can be done in the short term to avoid exposure to POPs. Here's what you need to know about them... #1 and #2: Dioxins and furans. Origins: Generated by incinerating chlorinated products, through some industrial processes (such as pulp and paper bleaching) and in forest fires where chlorinated pesticides have been used. Health impacts: Considered the most poisonous synthetic substances known. Causing damage in parts per quadrillion, the United States Environmental Protection Agency has declared that dioxins and furans have no safe level whatsoever. Widespread in human breast milk in many industrialized countries. Linked to cancer, immune and reproductive disruptions. Alternatives: Using other existing non-chlorinated industrial processes; reducing the production of PVC, the world's second most common plastic. #3: Polychlorinated biphenyls (PCBs). Origins: Produced as coolants and lubricants in electrical equipment and generated as a chemical manufacturing waste by-product. No longer manufactured in most industrialized nations (except Russia) but still widely used and stored. Health impacts: Acts as a cancer promoter. Can cause birth defects, immune and reproductive deficiencies, and neurological damage. Found in high concentrations among Northern peoples (i.e. the Inuit) and others with diets rich in fat. Alternatives: Many technologies currently in development, but all current disposal methods return some PCBs or other POPs back into the ecosystem. #4 to #11: DDT, chlordane, heptachlor, mirex, aldrin, dieldrin, endrin, and toxaphene. Origins: All are common pesticides used to kill mosquitoes, termites, soil insects, crop worms and weevils. Widely used in developing countries; use banned in industrialized countries, but still released through storage leaks and unsafe disposal. Health impacts: Generally act as cancer-causing agents and are linked to reproductive and nervous disorders. DDT, chlordane and heptachlor are commonly found in breast milk. Alternatives: Integrated pest management through combined biological, physical and mechanical means. (Biologically integrated pest control involves genetic mutation of crops, also highly controversial.) #12: Hexachlorobenzene. Origins: Fungicide for seed grains; also used as a chemical intermediary in the production of solvents and dyes. Widely banned as a fungicide. Large quantities still released as a waste by-product of chlorinated pesticides and plastics. Health impacts: Widespread in human milk, can cause liver and thyroid cancer, and harms immune and nervous systems. Alternatives: Switching to non-chlorinated chemical processes. Next week's conference will be the first UN meeting on POPs and will hopefully lead to a global treaty to decide their fate. One major issue will be whether to opt for gradual reduction (favoured by the chemical industry) or eliminate them altogether (favoured by public health and environmental groups). Most of the latter groups agree that even total elimination would only make the best of a bad situation: POPs have been around for 50 years and are so persistent they will probably be around for 50 more. "Industry groups will try to portray elimination as an extreme position," says Matthew Bramley of Greenpeace Quebec. "But elimination has already been adopted as an official position by Canada and most northern European countries." If successful, Bramley says, a POPs treaty would be bigger than the 1987 Montreal Protocol on ozone depletion: "The industrial sector involved is much larger and the health effects are more direct and dangerous." Public conferences on the dirty dozen take place Saturday, June 27 at 1:30pm (UQAM, room AM050) and Sunday, June 28 at 11 am (Bibliothèque nationale, 1700 St-Denis) Info: 933-0021
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They've been dubbed "the dirty dozen": 12 of the world's most notorious toxic substances. And at a conference sponsored by the United Nations Environment Programme (UNEP) beginning Monday in Montreal, delegates from over 100 countries will haggle over how to rub them out.