PCBs and POPs

by Bill Duesing

First broadcast on WSHU/WSUF-FM, November 7, 1997

The overpowering message I took away from last week's "Agricultural Chemistry Night" at the Connecticut Agricultural Experiment Station was that the chemists who create toxic pesticides and industrial chemicals have gotten us into quite an awful mess.

Tomorrow, at the same place in New Haven, The Northeast Organic Farming Association of Connecticut, or NOFA, holds its annual meeting, which is open to everyone who's interested in food grown without the use of toxic chemicals. A farmers' market and a pot luck lunch offer a taste of the bounty of Connecticut's organic farms and gardens. And, Dr. John Wargo from the Yale School of Forestry will talk on "Pesticides and Children."

The agricultural chemistry program featured presentations by four Experiment Station scientists about their ongoing investigations. The titles by themselves give a good idea of the issues: "Persistent Organochlorine Pesticides (POPs) in Soil and Produce," "The Effect of Food Preparation on Pesticide Residues," "PCBs in Fish from the Quinnipiac River," and "Environmental Issues Associated with the Use of Pressure-Treated Wood."

Dr. Mary Jane Mattina is studying chlordane, a POP. This insecticide was widely used in agriculture and around homes until 1988, when it was banned because of its toxic effects on humans and wildlife. Chlordane lasts for up to 20 years and is still widely present in Connecticut soils.

Some vegetables accumulate chlordane when they grow in polluted soils. Cucumbers and squashes are known to absorb this chemical. Dr. Mattina is trying to understand the ways that vegetables take up chlordane. Any notions about the precision of chemistry were shattered when she revealed that this pesticide is actually a variable mixture of up to 140 different chemicals.

Dr. Harry Pylypiw studies pesticide residues on produce and the extent to which they can be removed by washing. His good news was that over half the produce sampled had no detectable residues. However, over one third of produce tested does contain residues of one or more pesticides. Dr. Pylypiw carefully washed different fruits and measured how much of the residue was left. He found that some residues were removed by washing and others were not much affected, although he didn't know why.

Dr. Brian Eitzer is just beginning a study of polychlorinated biphenyls (PCBs) in fish caught in the Quinnipiac River near New Haven Harbor. PCBs were widely distributed as a result of various industrial applications until they were banned. Because they were designed not to break down, PCBs are now present in the sediments of most rivers. Some fish bio-accumulate this substance, which is really a mixture of up to 209 different compounds. PCBs can cause cancer and other serious health problems.

The fourth chemist, Dr. David Stilwell discussed his findings about arsenic and cadmium residues in soils under decks built of pressure-treated lumber, and on cloths wiped over this wood. These heavy metals are not good for humans and other living things. They are often taken up by plants.

With the help of chemists, humans have widely distributed millions of pounds of thousands of different synthetic chemicals, specifically designed to be toxic. No one knows how much of what has been spread where, what their exact compositions are, what their fate is in ecosystems, or what their health effects are. That's the chemical industry, for you!

The one positive note at "Chemistry Night" was that spreading compost and liming soil to near neutral reduce cadmium and lead problems.

Building soil health through additions of compost and minerals (such as limestone) is the cornerstone of organic gardening and farming. Some NOFA/CT members have used these practices successfully for over 50 years. Seventeen years ago the USDA reported that organic farming works and addresses many environmental problems.

Tomorrow, at NOFA's Annual Meeting at the Experiment Station in New Haven, Dr. Wargo will discuss pesticide regulation and the changes that we can expect under new legislation passed last year. Dr. Wargo is the author of Our Children's Toxic Legacy: How Science and Law Fail to Protect Us from Pesticides. He will speak at 2 o'clock. The organic farmers market is open from 11 to 1. Bring your favorite dish and a place setting and join us for Connecticut's best potluck at noon. For more information, call 203-484-2445.

See you there!

This is Bill Duesing, Living on the Earth

This page and its contents are copyright © 1997 by WSHU-FM, Fairfield, CT, and by Bill Duesing.