Food Quality Protection Act: 

 Cumulative Risk Assessment for the 

 Organophosphate Pesticides 



Roberta Spitko 



New England Fruit Consultants, Montague, MA 



The primary focus of EPA's Office of Pesticide 

 Programs activities over the past year has been the 

 development of a cumulative risk assessment for the 

 organophosphate pesticides (OPCRA). This risk 

 assessment is the most complicated, comprehensive 

 attempt to measure cumulative exposure to a particular 

 group of pesticides that has ever been undertaken. 



The OPCRA final document exceeds 5,000 pages 

 in length. The methodologies developed by EPA to 

 collect and analyze the data are extremely sophisticated 

 and complex and have also been a source of much 

 controversy in the agricultural stakeholder community. 

 EPA is relying heavily on the advice of the FIFRA 

 Science Advisory Panel, a panel of expert scientists, 

 especially those in statistical modeling and toxicology, 

 for validation of the methods used. These 

 methodologies have been developed over the past 5 

 years, and represent a significant advance in EPA's 

 abilities to evaluate pesticides in a comprehensive 

 manner. It must be emphasized that the current risk 

 assessment, which was released in January 2002 for 

 public and scientific comment, is a preliminary 

 assessment. The Agency expects a large number of 

 comments to be submitted until the comment period 

 closes on March 8, 2002. 



A cumulative risk assessment is the process of 

 combining exposure (the amount of pesticide to which 

 an individual is exposed) and hazard (the health effects 

 a pesticide could cause) from all substances that share 

 a common mechanism of toxicity. In assessing hazard 

 associated with the organophosphate pesticides, EPA 

 analyzed their common method of toxicity, inhibition 

 of acetylcholinesterase, as the means for assessing risk. 



The goal of the organophosphate cumulative risk 

 assessment (OPCRA) is to measure the probability of 

 exposure to more than one organophosphate pesticide 

 and to assess the effects of this combined exposure. 

 The assessment incorporates possible OP exposures 



from structural, recreational, and drinking water, as 

 well as from OP residues in consumed food. Each 

 component of the risk assessment uses the best 

 available data: data from surveys of what people eat 

 and drink, of their activities involving pesticide use 

 around the home and workplace, and monitoring studies 

 of pesticide residues in these environments. 



A comprehensive assessment of the 

 organophosphates may raise concerns with growers 

 about further restnctions on materials available for crop 

 production. However, the results of the OPCRA may 

 not have much effect on current OP use. Much work 

 has been done previously on the individual 

 organophosphates to reduce their risks as they go 

 through the FQPA-mandated tolerance reassessment 

 process. 



The risks for the individual OPs will be factored 

 into the cumulative equation at these lower levels. 

 Most structural and home-garden uses have already 

 been cancelled or significantly curtailed. Routes of 

 exposure through drinking water have already been 

 determined to be negligible. 



It must be noted again that the recently released 

 OP cumulative risk assessment is preliminary. EPA is 

 continuing to seek input from the scientific community 

 and stakeholders and is aware that revisions and 

 refinements will be necessary. Determining cumulative 

 exposure is a huge task, and this is the first time EPA 

 has attempted develop a comprehensive profile of 

 human exposure to a group of chemicals with common 

 modes of toxicity. It will be an evolving process that 

 will take years to refine. 



Following the comment period closure of March 

 8, 2002, EPA will consider submitted comments and 

 plans to issue a revised risk assessment in the summer 

 of2002. 



The preliminary OPCRA may be accessed at 

 www.epa.gov/pesticides/cumulative. 



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16 



Fruit Notes, Volume 67, Winter, 2002 



