Parathion exposure

The only approved use of methyl parathion is on crops, including crops used as foods. Effective December 31, 1999, the EPA cancelled the use of methyl parathion on many kinds of crops used as foods because of a concern for exposure risks to children and to workers. This action will reduce the risks to families of methyl parathion exposure from food. 

Often, absorption occurs by multiple routes in humans. Dean et al. (1984) reported deaths and toxic effects as well as lowered blood cholinesterase levels and excretion of urinary 4-nitrophenol in several children who were exposed by inhalation, oral, and possibly dermal routes after the spraying of methyl parathion in a house. In the same incident (Dean et al. 1984), absorption was indicated in adults who also excreted 4-nitrophenol in the urine, though at lower levels than some of the children, and in the absence of other evidence of methyl parathion exposure. In this study, the potential for age-related differences in absorption rates could not be assessed because exposure levels were not known and the children may have been more highly exposed than the adults. Health effects from multiple routes are discussed in detail in Section 3.2. 

ATSDR is conducting a health study to investigate the lasting health effects of methyl parathion exposure on children. In this study, ATSDR will be testing children in two states, Ohio and Mississippi. The principal Investigator is Dr. Rubina Imtiaz, ATSDR Division of Health Studies, 1600 Clifton Road, Atlanta, Georgia 30333. 

Hundreds of deaths associated with parathion exposure have been reported. These deaths have resulted from accidental, suicidal, and homicidal poisonings. It has been the cause of most crop worker poisonings in the United States. Fatal human poisonings have resulted from ingestion, skin exposure, and inhalation (with varying degrees of skin exposure). 

Peoples et al. (5) reported that 351 cases of occupational illness caused By parathion exposure were seen by California physicians in 1975. Seventeen of these cases can be regarded as worker reentry incidents. Knaak et aj. (6) reported a case of 118 worker illnesses from dialifor exposure in a California grape vineyard in 1976. Davies et al. ( 7) reported 2 cases (24 fieldworkers) involving parathion in Florida sweet corn. In 1975, one death was reported from North Carolina workers reentering a parathion-treated tobacco field 8). 

Urinary -Nitrophenol Concentrations in Acute and Chronic Parathion Exposures... 

The understandable correlation among careless technique, absenteeism, cholinesterase inhibition, and elevated average urinary PNP levels suggested that the latter was a highly reliable biological index of chronic parathion exposure and one that could ultimately predict chronic parathion toxicity. 

Once it became apparent that the urinary PNP was a specific and stable urinary metabolite, capable of reflecting parathion exposure, especially dermal, it was obvious that its measurement would provide useful information both in the acute poisoning and in the daily surveillance of the chronically exposed occupational worker. 

Ruckart, P. Z., Kakolewski, K., Bove, F. J., and Kaye, W. E. 2004. Long-term neurobehavioral health effects of methyl parathion exposure in children in Mississippi and Ohio. Environmental Health Perspectives 112 46-51. 

In March 1997, there were reported misuses of methyl parathion leading to prosecution. Over 15 000 homes and businesses in Mississippi and Ohio were sprayed with methyl parathion by unlicensed operators. Methyl parathion is prohibited for use indoors. Authorities had to relocate over 1100 people to temporary accommodations with clean-up costs approaching 50 million dollars. With these reported misuses, local veterinarians reported deaths of household pets due to methyl parathion exposure. In July 1997, there was also an illegal application of methyl parathion by an illegal applicator to control cockroaches in the Chicago area. 

Bradway, D. E., and Shafik, T, M. Parathion Exposure Studies. Gas Chromatographic Method for the Determination of Low Levels of p-Nitrophenol in Human and Animal Urine... 

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