(Beyond Pesticides, march 30, 2009) The burning of grass seed fields on more than 38,000 acres in Oregon has been a threat to public health for decades. Pesticide Use in Grass Seed Production: Dispelling the Field Burning Myth, a new report by Oregon Toxics Alliance, finds that grass seed fields are often sprayed with pesticides before and after field burning, which exacerbates the effects of the pesticides, creating toxics such as dioxins, cyanide, and hydrogen chloride.
The report identifies 56 different pesticides that are routinely used on Oregon grass seed fields, including 2,4D, captan, carbaryl, chlorothalonil, clopyralid, cyfluthrin, dicamba, dimethoate, diquat dibromide, glyphosate, MCPA, paraquat, thiram, and triclopyr, among others. These pesticides, many of which are linked to cancer, neurotoxicity, endocrine disruption and are irritants and sensitizers, are applied over several seasons and are then burned, multiplying the health risks of the pesticides. Their combustion produces thousands of tons of air pollution spreading dioxin, phosphorus pentoxide, hydrogen chloride, cyanide, sulfur dioxide, tetrachlorodibenzodioxin (tcdd-dioxin) and polynuclear aeromatic hydrocarbons (PAHS), which attach to the surface of the fine particles in the smoke.
According to the report, combustion of pesticides and their by-products result in significant chemical transformations. The report cites research showing previously deposited semi-volatile organic compounds, such as pesticides, re-volatilize to the atmosphere and/or degrade from soils and vegetation during the burning process. It also cites studies showing that pesticides transformed into small particulate and airborne compounds can be carried though the atmosphere far distances.
“These toxic substances are carried with the fine particles deep into the lung and directly into the blood stream where there are few defense mechanisms,” states Lisa Arkin, author of the report and executive director of the Alliance. “So it turns out that burning agricultural waste that has been sprayed with pesticides can cause a more serious health risk to anyone downwind from these operations than has been previously considered.”
“Inhalation of smoke from burning fields presents a serious threat to many patients with both lung and heart disease,” notes Robert Carolan, M.D., a Eugene-based pulmonologist. “It also presents a real risk to many others, including children and the elderly.”
The report rejects the argument that a ban on field burning will result in an increase in pesticide use. Field burning was banned in the state of Washington over a decade ago and their industry has continued to thrive. “With the tax credits and development of alternatives that have long been provided to the grass seed industry, it is now time to stop this dangerous practice,” declares Eugene Mayor Kitty Piercy.
According to the Alliance, there are a variety of practices and strategies that farmers can use to lessen their dependence on fertilizers and herbicides and avoid the need for fire including converting to organic agriculture, using different rotation crops such as Meadowfoam, using later flowering grass seed strains, mulching leftover grass stalks, composting leftover grass stalks for future soil amendments, and selling bailed leftover grass stalks as livestock feed.
The report has been submitted to the Oregon legislature in support of SB 528, which calls for the immediate cessation of the majority of field burning and is sponsored by legislators from the Willamette Valley.
The campaign to ban agricultural field burning, spearheaded by the Alliance and the Western Environmental Law Center, is supported by state and county elected officials as well as over 100 businesses and associations, including those in the outdoor recreation industry, farming, food products and distribution, financial services, restaurants, and the Lane County Medical Society representing over 700 physicians.