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Last Edited: 3/14/2008

Pesticide food poisoning from contaminated watermelons in California
Written: 1990

Aldicarb, a carbamate pesticide, is the most potent pesticide in the market, and has an LD50 of 1 mg/kg.  In the United States, it is illegal to use aldicarb on certain crops, including watermelons, because it is incorporated into the flesh of the fruit.  Once an accidental or illegal use of such a potent pesticide occurs, there is no easy way for the agricultural or public health system to protect the populace.  This paper describes the impact of one such event upon the health of individuals and the institutions of California. 

On July 4, 1985, California and other western states experienced the largest known outbreak of food-borne pesticide illness to occur in North America.  This was attributed to watermelons contaminated through the illegal or accidental use of aldicarb by a few farmers in one part of the state.  Within California, over 1,300 illnesses resulting from consumption of watermelons were reported to the California Department of Health Services (CDHS).  Of these, 77% were classified as being probable or possible carbamate illnesses.  Many of the case reports involved multiple illnesses associated with the same melon among unrelated individuals.  Seventeen individuals required hospitalization.  There were 47 reports of illness involving pregnant women, two of whom reported having subsequent stillbirths.  

To control the epidemic, it was necessary to embargo on July 4, and destroy all watermelons in the state, and to effect a field certification program.  The epidemic and costly resultant control measures illustrate the difficulties in assuring a set of crop specific regulations.   



Suggested Citation

  • Goldman LR, Smith DF, Neutra RR, Saunders LD, Pond EM, Stratton JW, Waller K, Jackson RJ, Kizer KW. Pesticide food poisoning from contaminated watermelons in California, 1985. Archives of Environmental Health 1990 45(4):229-236.