Rodale Institute Chief Scientist Dr. Elaine Ingham answers your questions and talks about what is going on under our feet nationwide.
Mark asks:
To what degree does composting decompose pesticides, antibiotics, and other chemicals? Totally? Partially? To safe levels? How usable is the resulting compost as fertilizer that contained pesticides, antibiotics, and other chemicals. Are there leftover residues that can be taken up by crops? What are the chances for pesticides and antibiotics specifically?
Dr. Elaine Ingham says:
To destroy, or decompose, antibiotics during composting, you have to have organisms growing so fast in the compost that temperatures rise above 131-degrees for 10 to 15 days. This will happen, as long as you have good mixes of bacteria, fungi, protozoa and a few beneficial nematodes in the compost pile. Worm composting also works if you are certain you have the broad diversity and activity of aerobic organisms working in the worm pile.
Decomposition of many pesticides during composting happens without any trouble, but a fair number of pesticides require special species of microorganisms to do the job of decomposition. Thus, it might be important to know what pesticides are present, and then make sure the right set of organisms are present during the composting process to grab those toxic materials and tie them up.
Heavy metals are a whole different set of considerations, but can be handled at low to intermediate concentrations by organisms in the compost pile. Composting will not decompose heavy metals, but rather incorporate them into the structure of organic matter, thus making them unlikely to impact or harm plant or animal life. However, inappropriate conditions during composting will mean the heavy metals are not properly handled.
Want to learn more? Join Dr. Elaine Ingham for a Life in the Soil three-day intensive or a single-day concentration class on soil biology, compost, compost teas or microscopy. {LEARN MORE}
My understanding is that metal organics are a serious problem. For years the pulp mill in Drydon Ontario allowed mercury to escape into the local river, thinking that it would quickly oxidise into Hg20. Instead bacteria changed it into HgCH3 (Methyl-mercury) which moves up the food chain.
This destroyed the sports fishery on the English River, and meant that the indians at Grassy Narrows could no longer eat the fish from the river.
The latest issue of Mother Earth News has an article about pesticides that can be applied to a field, grazed, the manure collected, composted, and is STILL deadly.
http://www.motherearthnews.com/killer-compost-herbicide-contamination-zl0z1211zkin.aspx
Aminopyralid (sold as Milestone, Milestone VM, Milestone VM Plus, Chaparral, CleanWave, ForeFront, GrazonNext, Opensight and PasturAll) is the chemical cited in this article.
Another article mentions Imprellis, from Dupont as having serious persistence issues.
Other economic poisons are equally long-lived. A good story on the web is that of Water Penny farm in Virginia and their problem with picloram in hay mulch.
Also a problem are the conversion products of pesticides. EPA looks at pure pesticides, but some pesticides Atrazine and other triazines come to mind convert very quickly to alternate substances in water. Thions like malathion, parathion, diazinon, convert to oxon forms. The old apple insecticide Alar converted to methylated hydrazine, a serious carcinogen. It not whether or not things compost and how quickly, it’s what they compost to.
You are right to be concerned about MeHg; and you have a good handle on chemistry too. Remember that your body burden of MeHg differs greatly from that of your parents whose body burdens differ from that of your grandparents. We are exposed to more MeHg. The National Park Service did a study called WACAP [western airborne contaminant assessment program] last year and reported finding mercury, dieldrin and DDT in high-elevation brook trout in national aprks free of industry. These are legacy poisons moving through the food chain – atmospherically deposited 50 years ago in America’s most prsitine waters.
This stuff is not supposed to be in national parks – industry said that these economic poisons could be used safely, and their word was false.
The story of mercury is more awesome than you know. A dreadful disease of babies and infants was callled “Pink Disease” and I believe there’s a pink disease survivors group on the web. Pink disease was due to mercury exposure in medicines. For example, my 1906 Squibb Material Medica and Price List contains their best-selling children’s tonic. The main ingredient is “corrosive sublimate” which was a pharmaceutical term for mercury.
US shipments of corn seed coated with MeHg fungicide to Iran were eaten rather than sown – disabling 10,000′s and calling attention to MeHg poisoning.
The Faroe Island studies and others now confirm the nature of the poison, MeHg is a fetotoxic, meaning that MeHg poisons the fetus rather than the mother who carries the child. A child is born poisoned from the mother’s exposure.
I urge you to take a better look at the food chain of your river and watch how the burden of MeHg moves, bioconcentrating and bioaccumulating in the chain.
There are excellent historical books with photos of pink-diseased infants [acrodynia] on the shelves of the local medical university library, and I urge you to look at them.
Googling, you will find that MeHg is an epigenetic toxin and it plays havock with the epigenetic “breaker box” that guards our genetic circuits.
“a fair number of pesticides require special species of microorganisms to do the job of decomposition” –> which are this pesticides and what microorganisms do they need?