Rotenone and Public Health

The federal Environmental Protection Agency (EPA) controls pesticide use in partnership with state agencies. Before allowing application of a pesticide, the EPA studies each one to be sure they do not pose risks to human health and the environment.

The EPA regularly reviews all pesticides. However, the EPA does require precautionary measures such as wearing protective clothing for the applicators and restricting drinking and/or contact with treated water according to criteria listed in the product label. In their re-registration assessment, the EPA concluded that using rotenone according to product label instructions does not pose unreasonable risk to human health or the environment. However, the EPA does recommend precautionary measures such as wearing protective clothing for the applicators and closing water bodies treated with rotenone to swimming for a few days following treatment. The World Health Organization classifies rotenone as moderately hazardous because it may be absorbed by ingestion or inhalation. Inhalation of concentrated rotenone in the powder form is the most direct threat to humans, and caution is required during handling. The Alaska Department of Environmental Conservation requires that rotenone applicators receive state certification in applying pesticides.

There is a lot of information currently available concerning rotenone and human health and safety issues. Much of this information is synthesized in the following websites:

Millions of dollars have been spent in the U.S. on research to evaluate the safety of rotenone, and the majority of this work has focused on human health questions. Results of these studies confirm that rotenone does not cause birth defects, reproductive dysfunction, gene mutations or cancer. No fatalities in humans have been reported in response to proper use of rotenone products. Drinking rotenone poses little risk to humans because of the low concentration used and rapid degradation in the aquatic environment. Drinking rotenone from waters treated with rotenone poses little risk to humans because of the low concentration used for fish management and digestive processes that break much of the rotenone down. For example, it is estimated that a 160-pound adult would have to drink 23,000 gallons, and a 22-pound child would need to drink over 1,400 gallons of rotenone-treated water at one sitting to receive a lethal dose. Although ingestion of rotenone from rotenone-killed fish is not considered harmful, the EPA does not recommend that rotenone-killed fish be used for human consumption because no tolerance (acceptable residue level permitted in fish flesh) has been set by the EPA.

There have been highly publicized concerns that rotenone exposure could be associated with Parkinson's disease. Given sufficient exposure, rotenone may cause specific damage to nerve cells causing signs of neurotoxicity similar to Parkinson’s disease, but rotenone has never been shown to actually cause Parkinson’s disease. Recent toxicology and epidemiology studies linking rotenone exposure to Parkinson’s disease remains inconclusive. Animal toxicology studies demonstrating Parkinson’s-like effects were conducted using routes of and long-term exposure regimes not germane to potential human exposure associated with fishery uses. The epidemiology studies linking Parkinson’s disease to farmers with a history of using of pesticides, including rotenone, are largely qualitative in nature and paid little or no attention to personal hygiene, safety and safety equipment which use is now mandatory in fishery applications. For the rotenone applicator, who is most at risk for exposure, the use of required PPE will significantly reduce, if not eliminate, exposure. For the general public, restricted access to the treatment area until rotenone subsides to safe levels and the use of potassium permanganate to detoxify water leaving the treatment area will virtually eliminate exposure. The EPA states rotenone concentrations below 90 parts per billion are safe for human contact and below 40 parts per billion are safe for drinking. Target rotenone concentrations used for fish control in Alaska have always been far below the limit deemed safe for human contract.