Pyrethrin and pyrethroid illnesses in the Pacific northwest: a five-year review.
OBJECTIVE
Pyrethrin and pyrethroid insecticides are commonly applied in homes and businesses and on some agricultural crops. This research used a two-state regional approach to analyze reports of acute pesticide poisonings due to pyrethrin and pyrethroid insecticides.


METHODS
The Washington State Department of Health and the Oregon Public Health Division collected pesticide poisoning surveillance data from 2001 through 2005. Cases were included if they involved exposure to at least one pyrethrin or pyrethroid insecticide. Descriptive statistics were calculated; differences between categories were assessed using Chi-square analysis.


RESULTS
A total of 407 cases fit our definition. Overall, the rate of poisoning in Oregon was significantly higher than in Washington (incidence rate ratio 1.70, 95% confidence interval 1.40, 2.07), and rates for both states generally increased during the time period. For both states, most exposures resulted in low severity illnesses (92%), and most were classified as possible cases (73%). Only about one-fourth of cases were related to a person's work. The most common category of clinical signs and symptoms of illness was respiratory (52% of cases), followed by neurological (40% of cases). Exposure route was predominantly inhalation; there was no association between route and case severity. There was a significant association between illness severity and losing time from work or regular activities (p<0.0001).


CONCLUSIONS
Although the majority of pyrethrin and pyrethroid poisoning cases were low in severity, adverse reactions have occurred, as transpired in Oregon in 2005. Regional analysis has the potential to improve the surveillance system and provide unique opportunities for targeting preventive interventions.
Oregon Department of Human Services, Public Health Division, Office of Environmental Public Health, Toxicology, Assessment, & Tracking Services, Oregon Worker Illness and Injury Prevention Program, Portland, OR 97232, USA. jaime.walters@state.or.us
Jaime K
JK
Walters
Laura E
LE
Boswell
Mandy K
MK
Green
Michael A
MA
Heumann
Lauren E
LE
Karam
Barbara F
BF
Morrissey
Justin E
JE
Waltz
D000293:Adolescent; D000328:Adult; D000368:Aged; D004651:Employment; D004781:Environmental Exposure / Q000009:adverse effects / Q000032:analysis; D005260:Female; D006801:Humans; D007306:Insecticides / Q000737:chemistry / Q000506:poisoning*; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009922:Oregon / Q000453:epidemiology; D011041:Poisoning / Q000453:epidemiology / Q000209:etiology / Q000503:physiopathology; D011159:Population Surveillance; D011722:Pyrethrins / Q000737:chemistry / Q000506:poisoning*; D014861:Washington / Q000453:epidemiology; D055815:Young Adult
D007306:Insecticides; D011722:Pyrethrins