USDA-Agricultural Research Service (ARS) scientists have announced that chicken feed supplements which contain arsenic are accumulating in fields building their concentrations in agricultural soils over time--and possibly migrating into nearby streams and rivers.
Many factory farms and poultry producers often supplement chicken feed with roxarsone, a compound containing arsenic, to control parasites and promote weight gain. Most of this arsenic is excreted by the chickens and then becomes mixed in with sawdust and other litter materials used in poultry houses. Farmers then use this litter as fertilizer for amending their crop soils.
Among other sources, arsenic is found in pesticides, table salt, tap water, pigments, fungicides, insecticides, and treated wood. Lesser known sources are those in animal products such as chickens who absorb a percentage of the arsenic which may then be absorbed by humans who consume chicken products.
In 2006, the FDA also approved the spraying of chicken meat with viruses in an effort to stop bacteria. The virus-cocktail spray, called LMP 102, is a mixture of six viruses called bacteriophages. The combined toxic load from conventionally raised chickens is presenting a high level of toxicity into the food supply. Levels of arsenic today are 1000 times higher than in primitive societies.
According to an article in the April 9, 2007 issue of Chemical & Engineering News, chicken feed may pose health risks to humans who eat meat from chickens that are raised on the feed
Chemist Clinton Church, who works at the ARS Pasture Systems and Watershed Management Research Unit in University Park, Pa., led this research. His partners included University Park soil scientist Peter Kleinman, support scientist Lou Saporito, research leader Ray Bryant and University of Maryland Eastern Shore scientist Arthur Allen.
For two years, the team measured arsenic levels in runoff that flowed from farm fields into seven drainage ditches in the Delmarva (Delaware, Maryland, Virginia) Peninsula, an area dominated by large-scale poultry production for decades. Runoff measurements indicated that annual arsenic losses from these fields could range from 0.004 kilograms per hectare to 0.071 kilograms per hectare. Runoff with the largest arsenic loads was recorded in a ditch closest to a main point source of the contaminant—a shed where litter was stored.
They team also tracked phosphorus runoff, as it are known to interact and compete with arsenic. During storm events, both pollutants exhibited similar behavior. However, their concentrations differed significantly between ditches and showed no seasonal patterns. This suggests that management practices for phosphorus are unlikely to be applicable to arsenic.
This study highlights the importance of controlling point sources of arsenic and other chemicals and suggests that management practices—such as properly storing dry litter and controlling litter spills outside storage facilities—can help protect local regions from the migration of arsenic and other agricultural pollutants.
Results from this research will be published in the November/December 2010 issue of the Journal of Environmental Quality, a publications of the American Society of Agronomy, the Crop Science Society of America, and the Soil Science Society of America.
The Journal of Environmental Quality is a peer-reviewed, international journal of environmental quality in natural and agricultural ecosystems published six times a year by the American Society of Agronomy (ASA), Crop Science Society of America (CSSA), and the Soil Science Society of America (SSSA). The Journal of Environmental Quality covers various aspects of anthropogenic impacts on the environment, including terrestrial, atmospheric, and aquatic systems.
The American Society of Agronomy (ASA) www.agronomy.org, is a scientific society helping its 8,000+ members advance the disciplines and practices of agronomy by supporting professional growth and science policy initiatives, and by providing quality, research-based publications and a variety of member services.