Making Use of Pesticide Data to Prevent Poisonings

The thousands of workers who repeatedly apply certain pesticides to California’s crops are subject to a medical testing program that’s meant to prevent pesticide poisoning in workers. As the program currently stands, there’s no way of knowing whether or not it’s working, and PSR-LA  along with Pesticide Action Networks of North America and the Association of Public Health Officers is sponsoring legislation to fix it: AB 1963 (Nava), Tracking Pesticide Poisoning in California. This bill proposes to make important changes in the current program whose purpose is to protect the health of farm workers from the harmful effects of overexposure to toxic pesticides.

The Cholinesterase Medical Supervision Program requires workers to receive periodical medical tests which measure the amount of cholinesterase in the blood. The enzyme cholinesterase works to regulate the activity of one of the brain’s most important neurotransmitters, and therefore is vital for the proper transmission of nerve impulses. The pesticide classes known as organophosphates (OPs) and n-methyl carbamates (CB) are known to inhibit cholinesterase, thereby decreasing the level of this important enzyme in the blood. As a result, the state has found it necessary to test the cholinesterase levels of those who are exposed to these pesticides on a regular basis.

Between the years of 1998 and 2000 about a third of all the pesticide related illnesses in agricultural workers were linked to exposure with these chemicals. Although the use of OP and CB pesticides has decreased by about 50% in recent years, the use of these compounds is still dangerously high – in 2008 alone 5 million pounds of  OPs and CB pesticides were applied to California fields.

Under the program, there is no provision requiring the results of such tests to be reported to any state agency that would have the power to collaborate with other authorities in order to implement necessary safety measures or regulations concerning these potentially harmful pesticides. Simply, with the current system, organizations such as the California Department of Public Health (DPH), Department of Pesticide Regulation (DPR), and the Office of Environmental Health Hazard Assessment (OEHHA) don’t have a way of reviewing the records of workers cholinesterase levels to take preventative action.  These records only come to the attention of state agencies after a poisoning incident has already occurred, leaving no room for any sort of prevention based on existing cholinesterase tests.

Exposure to OPs and CB can cause serious health problems. Symptoms of overexposure can occur in as little as 48 hours and include headaches, dizziness, nausea and vomiting, diarrhea, excessive salivation, tightness of the chest, muscle twitching and pupil constriction. Carbamates has a reversible effect on cholinesterase levels are reversible, meaning that they will return to normal in a short period if exposure is avoided. However, the inhibition of cholinesterase levels by organophosphates is permanent and levels will only return to their previous state after the body has had a significant amount of time to manufacture the enzyme itself. OP poisoning can also cause poor birth outcomes in pregnant women and lower sperm count and semen quality in men. Other reproductive effects include an increased risk in spontaneous abortion, fetal death, and a weakened immune system.

The new legislation proposed by Assembly Member Pedro Nava would effectively ensure the accountability of the Cholinesterase Medical Supervision Program. The new bill:

• Would require the laboratory performing the cholinesterase testing to electronically report all results to the DPR.
• DPR would be required to share its database with the DPH and the OEHHA and would be required  to work with these agencies to produce  report on the program.
• A medical supervisor designated by a physician would be required to send a copy of the cholinesterase testing results and communicate any pertinent recommendations to the worker with 14 days of the test.

This new legislation has the potential to prevent pesticide poisonings in California’s farm workers and provide the necessary data to reveal where the state needs to tighten regulations of neurotoxic OP and carbamate pesticides.

To find out how you can get involved in this issue as a health advocate, contact Martha Dina Arguello at (213) 689-9170, ext. 101.