Although proximity to the spraying of humans may be an issue, refuge during the spraying is possible, while it is impossible to entirely avoid exposure to insects throughout the summer. In contrast, when insecticide is sprayed, individuals can be specifically instructed to take cover during those times, and if necessary shelter could be provided to those individuals with inadequate housing, such as migrant workers.
Step 4. Risk characterization. What is probability of individual or population having adverse health effect? Risk characterization evaluates data from dose-response assessment and exposure assessment (steps 2 and 3). Risk characterization indicates that Mexican-Americans, many of which are agricultural workers, are more vulnerable to pesticide exposure than other groups.
Although it is argued that the poor or uneducated would not follow the safety precautions required by the Malathion application program, this is also true of individuals who fail to take precautions against West Nile. Uninformed residents, for example, could be outside during aerial spraying, or they could handle or eat matter that contains residues from application of the pesticide -- but the poor might be even more apt to spend long hours working outside, where mosquitoes breed, and are unable to afford to mend screens, use insecticide or have adequate long-term shelter to protect themselves against the insects.
The idea that the money spent spraying Malathion could be better directed to educational efforts is in...
Given the risk to individuals of Mexican origin, disseminating this information in Spanish as well as English, providing access to shelter during the spraying might answer some of the critic's concerns. Of course, it is true that some of the implications of Malathion on the environment, such as its effects on mosquito predators remain an unknown. But it could also be countered that the mutability of the virus, that the ability of the mosquitoes to multiply, the year's weather conditions and other favorable environmental factors to insect reproduction and/or creating standing water pools near humans is also in doubt. Thus, erring on the side of caution and spraying with Malathion seems like the better option.
References
Agency for Toxic Substances and Disease Registry. (2005). Toxicologic information about insecticides used for eradicating mosquitoes. Malathion (CAS Number 121-75-5).
Retrieved July 18, 2008, from h http://www.atsdr.cdc.gov/consultations/west_nile_virus/Malathion.html.
Center for Disease Control and Prevention. (2007). 2006 West Nile Virus activity in the United States. West Nile Virus Statistics, Surveillance, and Control. Retrieved July 18, 2008, at http://www.cdc.gov/ncidod/dvbid/westnile/wnv_factsheet.htm
