Karpati AM, Perrin MC, Matte T, Leighton J, Schwartz J, Barr RG. 2004. Pesticide Spraying for West Nile Virus Control and Emergency Department Asthma Visits in New York City, 2000.Environmental Health Perspectives, 112 (11): 1183-1187. This study examined potential associations between residential neighborhood ground spraying of pyrethroid pesticides in New York City (July-September 2000) to control the mosquito vectors of West Nile Virus and asthma-related public hospital emergency department (ED) visits October 1999-November 2000). In their analyses, the research team controlled for season, day of week, and daily outdoor temperature, precipitation and outdoor levels of particles and ozone measured at central sites. The results, across dates and zip codes (n=162), found no statistically significant relative risks of increased asthma-related public hospital ED visits with pesticide spraying in the neighborhoods, for all ages and for children. Thus, while previous case reports suggested pyrethroid pesticide exposure was related to an individual’s asthma exacerbations, these data suggested there were no similar population-level effects in New York City.