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Welcome to PSR's Environmental Health Policy Institute, where we ask questions -- then we ask the experts to answer them. Join us as physicians, health professionals, and environmental health experts share their ideas, inspiration, and analysis about toxic chemicals and environmental health policy.

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Tallying the True Cost of Industrial Agriculture

By Ted Schettler, MD MPH

This essay is in response to: How does our food production system drive our exposure to toxic chemicals?

On a cold winter day in a Michigan supermarket I can find asparagus and mangoes from Peru, lettuce from California, tomatoes from Florida, and apples that have been in cold storage since the fall harvest. Frozen, canned, and other processed food is also abundant. Between the supermarkets scattered throughout my city are dozens of convenience stores and fast food restaurants. There is plenty to eat, much of it very cheap. But what are we really eating?

We are increasingly aware of the many ways today’s food system is driving chronic disease patterns that challenge the health care system and drive up health care costs. The growing obesity epidemic, patterns of cardiovascular disease, and diabetes are directly related to diet, along with cognitive decline and dementia and various kinds of cancer, among others. Toxic chemicals play a troubling role in this picture, too.

Changes in food production, processing, storage, and distribution over the past 50-100 years have dramatically altered what we eat. New technologies, social structural changes, market forces, advertising, and government subsidies have all contributed. Along the way we have developed a national diet high in processed food with too much salt, unhealthy fats, sugar, and refined carbohydrates; and foods from far places—all too often dependent on heavy doses of pesticides, synthetic fertilizer, and fossil fuel.

Strictly speaking, food is comprised of chemicals. We depend on amino acids, fats, carbohydrates, vitamins, antioxidants and countless other substances for nourishment and to maintain health. But some chemicals in food can be harmful. A 1967 report from the National Academy of Sciences, “Toxicants Occurring Naturally in Foods,” includes chapters on goitrogens and estrogens in food, carcinogenic natural products, naturally occurring stimulants and depressants, and so on. We know to be careful when gathering mushrooms to eat in the forest—mistakes can be costly. But what about chemicals added to food or more broadly to the food production system? Do they pose risks? To whom?

Today’s dominant food system is heavily reliant on inputs of fossil fuels and synthetic chemicals, including pesticides and fertilizers, hormones, growth promoters, additives in food processing, and packaging materials. They boost yields, speed time to market, and protect against spoilage. But they may also pose risks. Here are a few examples.

Conventional farmers use enormous quantities of insecticides, herbicides, and fungicides during food crop production. Many of these are hazardous chemicals that can cause cancer, reproductive and developmental disorders, and neurological and immune system problems, among others. Farm workers, their families, and agricultural communities are often disproportionately exposed and suffer ill effects.

The Salinas Valley of California includes almost 225,000 acres of various crops, including nearly 80% of US lettuce production. In 2000, approximately 570,000 kg of herbicides, fungicides, and insecticides were applied to this area, nearly half of which were organophosphates. For six years, scientists from the University of California Berkeley have studied the impacts of prenatal organophosphate exposures on brain development of children of agricultural workers in this area. They report that children whose mothers had the highest levels of urinary organophosphate metabolites during pregnancy have impaired mental development, decreased attention spans, and the most cases of pervasive developmental disorder. Organophosphate residues also show up on conventional produce and, in the aggregate, can result in exposures in consumers that exceed EPA safety levels. Their impacts on brain development of children in the general population are unknown. Still, no one should avoid eating fruits and vegetables because of concern about pesticide residues. Vigorous washing will remove much of the residue from conventionally grown crops. Organic produce avoids the problem entirely, but not everyone has access to or can afford it.

Synthetic industrial chemicals such as phthalates, adipates, organometals, and others can migrate from packaging into food. Bisphenol A (BPA) leaches into food and beverages from the resin lining the inside of most cans. Dietary exposures help to explain why over 90% of people in the US have measureable levels of BPA metabolites in their urine. Numerous laboratory studies show that BPA is an extraordinarily biologically active chemical, with multiple mechanisms of toxicity. Relatively low-level exposures in laboratory animals can alter reproduction and development and increase the risk of breast cancer, prostate cancer, and diabetes. Human studies are in their very early stages, but many scientists and others believe we already know enough to take action to reduce exposures, including from dietary sources. The FDA continues to deliberate and has so far failed to act. Several states have banned BPA in food and beverage containers intended for infants and children, but these steps will not protect the developing fetus.

Arsenic is a carcinogen and increases the risk of cardiovascular disease and diabetes. Arsenic compounds are intentionally fed to poultry in large confined feeding operations to control intestinal parasites and promote growth. Some of the arsenic gets into the meat and is consumed. Some is excreted in manure that is spread onto farm land. From there, arsenic can leach into groundwater supplying drinking water to nearby communities.

Similarly, nitrate from fertilizer percolates through the soil and contaminates groundwater in many areas of the US. During some seasons the levels are extraordinarily high and the water is unsafe to drink. Excessive nitrate exposures can increase the risk of “blue baby” syndrome—by altering the capacity of hemoglobin to transport oxygen. But nitrate can also interfere with iodine uptake into the thyroid gland, increasing the risk of hypothyroidism and impaired neurodevelopment of children whose mothers may be affected during pregnancy. This may be particularly problematic in women who already have subclinical hypothyroidism or inadequate dietary iodine—increasingly common in the US. Nitrate also runs off into surface waters, resulting in algal blooms and eutrophication downstream. The dead zone in the Gulf of Mexico is to a large extent the result of agricultural practices hundreds of miles away.  

Today’s industrial agriculture is heavily dependent on fossil fuels at every stage, including land preparation, planting, cultivation, harvesting, transport, processing, and distribution. This results in large emissions of air pollution, including greenhouse gases, from fuel combustion and other activities.      

We can see from these few examples that many of the true costs associated with this industrial model are nowhere to be found at the checkout counter of the corner store or supermarket. In fact, they don’t show up anywhere on the food system balance sheet. They have been externalized to individuals, families, communities, and the health care system.

The Food and Drug Administration, Environmental Protection Agency, and Department of Agriculture have been charged with overseeing our food and agriculture system but this oversight sometimes falls short because of political pressure, limited resources, or limitations of statutory authority. The larger problem, however, is systemic.

Fred Kirschenmann from the Leopold Center for Sustainable Agriculture at Iowa State University reminds us that today’s dominant agricultural system is based on underlying assumptions of cheap energy, abundant water, and climate stability. Each of these has become increasingly untenable. Agriculture and food systems will need to be designed for local circumstances and move away from today’s heavy emphasis on chemical and fossil fuel inputs. Agricultural technologies must be applied in ways that work within the healthy functioning of natural and social systems. This approach can extend to food processing and include developing new materials for packaging, based on principles of green chemistry, that can actually improve food safety. Opportunities abound for cross-cutting solutions. They require political will and our commitment to the prevention of disease and disability and protection of the integrity of ecological systems on which human health depends.

Comments

Roderick Wood said ..

I agree with everything written above. AS an 81 year old retired LPN i have some knowledge of above of above material.

February 26, 2011

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