By Peter Montague
A two-year study of dioxin in the US Great Lakes has concluded that 86% of dioxin sources could be eliminated without economic sacrifice, and possibly with economic gains. The study was conducted by a team of researchers at Queens College in New York, led by Dr Barry Commoner.
Dioxin has emerged in the past 15 years as one of the two or three most dangerous chemicals ever tested. Intensive study has confirmed that dioxin acts as a powerful "growth dysregulator", an "environmental hormone" that interferes with normal growth and development in fish, birds, reptiles, amphibians and mammals, including humans.
Dioxin disrupts the central nervous system, the immune system, the hormone (endocrine) system and the reproductive system, preventing normal growth and development of the young and causing a variety of cancers.
Sources
Dioxin is never intentionally manufactured (except for laboratory purposes), but occurs as an unwanted by-product of many industrial processes. A recent estimate of annual worldwide dioxin production (which amounts to 3000 kg per year) indicates that major sources of dioxin include:
- municipal solid waste incinerators (1130 kg, or 37.6% of world total);
- cement kilns burning hazardous waste (680 kg, or 23% of total). Only cement kilns in the US burn hazardous waste, and these incinerators produce 13 times as much dioxin, per kilogram of cement manufactured, as cement kilns that do not burn hazardous waste.
- steel smelters (350 kg, 12%);
- cement kilns not burning hazardous waste (320 kg, 11%);
- biomass combustion (350 kg, 12%). This is from forest fires and commercial and residential wood burning. Trees do not naturally produce dioxin. But forests may be treated with chlorinated pesticides, which produce dioxins when burned. Alternatively, airborne dioxins may settle onto trees and be absorbed into the leaves and wood; when these later burn, the dioxin may be released into the atmosphere again. The researchers who developed these global estimates don't know which explanation is correct.
- medical waste incinerators (84 kg, 2.8%);
- secondary copper smelting (78 kg, 2.6%);
- automobiles burning leaded petrol (11 kg, 0.4%). Cars burning leaded petrol emit nine times as much dioxin, per litre of fuel, as cars burning unleaded petrol.
- automobiles burning unleaded petrol (1 kg, 0.03%).
These estimates are subject to large uncertainties because almost nothing is known about dioxin sources in the former Soviet Union, China and India. Furthermore, estimates of total dioxin falling onto the earth's surface worldwide (13,100 kg) are about four times as large as total estimated worldwide emissions. Thus no-one is sure where all the world's dioxin is coming from.
One thing is certain: dioxin is not coming from natural sources. Study of the sediments of lakes has shown that there was very little dioxin in the environment prior to 1940.
Despite these major uncertainties, dioxin emissions into the Great Lakes have been studied carefully by Commoner and associates, who identified 1329 individual sources. Of these, 106 account for 86% of the dioxin entering the Lakes.
The bulk of Commoner's report is an economic analysis of the feasibility of eliminating the sources of dioxin from medical waste incinerators, municipal solid waste incinerators, iron ore sintering plants, paper mills and cement kilns burning hazardous wastes.
Prevention or control?
Commoner takes a modern "pollution prevention" approach: he looks for ways to change production processes to avoid the creation of dioxin. Throughout the study, Commoner discusses the alternative approach — pollution control — and shows that it cannot reduce dioxin emissions to zero. Only eliminating the creation of dioxin by changing production technologies can achieve zero discharge of dioxins.
Despite prominent use of the term "pollution prevention" inside EPA (where they've even turned it into the buzz word "P2"), Commoner shows time after time that EPA and certain of the "big 10" environmental groups who are talking about reducing dioxin emissions under the Clean Air Act of 1990 are all stuck in old-style "pollution control" debates.
(The Clinton Administration and some of its acolytes in the Washington environmental community revealed their contempt for real pollution prevention in July when they helped Congress repeal the Delaney clause. Since 1958, the Delaney clause had prohibited the addition of known carcinogens to processed foods — the only US environmental law truly based on prevention. Now the Delaney prohibition has been repealed, replaced by a risk assessment process which allows "safe" amounts of cancer-causing chemicals to be added to food. In the unprincipled world of Washington environmental politics-and-money, this is being touted as progress.)
At present in Washington, P2 is just so much eyewash.
Commoner, on the other hand, applies the principle of pollution prevention aggressively, and in novel ways:
- Commoner shows that medical waste incinerators around the Great Lakes could all be shut down affordably and replaced by autoclaving (essentially a large pressure cooker that sterilises) followed by land filling. Autoclaving and land filling are an affordable, dioxin-free alternative to medical waste incinerators.
- Commoner shows that all municipal solid waste incinerators could be closed and replaced by dioxin-free intensive recycling programs — at a net saving of $536 million each year for Great Lakes communities.
- Commoner shows that pulp and paper mills could readily shift to totally chlorine-free technologies, thus completely eliminating the sources of dioxin in paper mills. Real pollution prevention is affordable.
- Commoner shows that chlorinated solvents and oils could be eliminated from iron sintering plants, thus eliminating the sources of dioxin from these facilities.
- Commoner shows that 75% of all cement is manufactured without using hazardous waste as a fuel, and that therefore it would be relatively easy for government to outlaw use of hazardous waste as a fuel in cement kilns.
Commoner's clear quantitative analysis and low-key advocacy offer real hope that dioxin could be brought under control nationwide. Unfortunately, Commoner starts his thinking from a place quite different from the place where EPA and the big environmental lobbying groups start their thinking.
Commoner boldly examines the production processes that are creating dioxin — production processes that are traditionally considered the exclusive domain of the so-called "private sector" — and suggests how they could be modified to prevent pollution. (It seems odd that this sector retains the label "private" even though its decisions have polluted every square metre of the planet with powerful poisons.) Until the environmental community adopts an approach as bold as Commoner's, talk of P2 will remain nothing more than a cynical cover for business as usual.
[From Rachel's Environment & Health Weekly.]