Factory farms - also known as Intensive Livestock Operations - produce staggering amounts of animal wastes. The way these wastes are stored and used has profound effects on human health and the environment.
On most factory farms, animals are crowded into relatively small areas, their manure and urine are funneled into massive waste lagoons. These cesspools often break, leak or overflow, sending dangerous microbes, nitrate pollution and drug-resistant bacteria into water supplies. For example, nitrates often seep from lagoons and sprayfields into groundwater. Drinking water contaminated with nitrates can increase the risk of blue baby syndrome and spontaneous abortions. Several disease outbreaks related to drinking water have been traced to bacteria and viruses from waste.
Even if none of these problems occurs, the lagoons still release toxic gases such as ammonia, hydrogen sulfide and methane. Their horrible stench and toxic chemicals harm workers and nearby residents. For instance, one gas released by the lagoons, hydrogen sulfide, is dangerous even at low levels. Its effects - which are irreversible - range from sore throat to seizures, comas and even death. Other health effects associated with the gases from factory farms include headaches, shortness of breath, wheezing, excessive coughing and diarrhea.
The farms often spray the manure onto land, ostensibly as fertilizer - these "sprayfields" bring still more of these harmful substances into our air and water. Although manure can be an excellent fertilizer when it is applied at rates that crops can absorb, it must be safely - and sensibly - applied. But factory farms often produce far more manure than their land requires, and they can overapply it to fields, causing it to run off the fields and into rivers and streams. Farmers may also spray when it is rainy or windy or when there is snow on the ground. In addition, the act of spraying wastes increases evaporation and vaporization of pollutants.
On top of this, the widespread use of antibiotics also poses dangers. Large-scale animal factories often give animals antibiotics to promote growth, or to compensate for illness resulting from crowded conditions. These antibiotics are entering the environment and the food chain, contributing to the rise of antibiotic resistant bacteria and making it harder to treat human diseases.
The natural environment also suffers in many ways from factory farming practices. Sometimes the damage is sudden and catastrophic, as when a ruptured lagoon causes a massive fish kill. At other times, it is cumulative - for example, when manure is repeatedly overapplied, it runs off the land and accumulates as nutrient pollution in waterways. Phosphorus and nitrogen threaten water quality. In excessive amounts, nutrients often cause an explosion of algae that robs the water of oxygen, killing aquatic life. Manure can also contain traces of salt and heavy metals, which can end up in bodies of water and accumulate in the sediment, concentrating as they move through the food chain.
When factory farms move into a community they promise increased tax revenues for the county, better markets for local farmers, jobs, and more commerce for businesses. However, studies show that large-scale livestock operations usually import their feed and equipment from outside of the county, export the finished product, and degrade the local roads with their trucks, bringing little benefit of any kind.