Development of models to predict dose of pesticides in professional turf applicators

Abstract

Epidemiologic studies designed to assess the chronic effects of pesticides are limited by inadequate measurements of exposures. Although cohort studies have been initiated to evaluate the effects of 2,4 -dichlorophenoxyacetic acid ( 2,4 -D ) and other pesticides in professional turf applicators, they may have limited power to detect significant health risks and may be subject to bias from exposure measurement error. In this study, the doses of 2,4 -D, mecoprop [ 2 -( 4 -chloro -2 methylphenoxy ) propionic acid, MCPP ] and dicamba ( 3,6 -dichloro -o -anisic acid ) were evaluated in a group of 98 professional turf applicators from 20 companies across southwestern Ontario. During a 1 -week period ( Saturday to Thursday ), the volume of pesticide ( active ingredient ) applied was only weakly related to the total dose of 2,4 -D absorbed ( R 2 = 0.21 ). Two additional factors explained a large proportion of variation in dose: the type of spray nozzle used and the use of gloves while spraying. Individuals who used a fan -type nozzle had significantly higher doses than those who used a gun -type nozzle. Glove use was associated with significantly lower doses. Job satisfaction and current smoking influenced the dose but were not highly predictive. In the final multiple regression models predicting total absorbed dose of 2,4 -D and mecoprop, approximately 63 -68% of the variation was explained. The future application of these models for epidemiologic research will depend on the availability of information and records from employers, the feasibility of contacting study subjects and cost.

Dermal absorption of 2,4-D: a review of species differences

“…Finally, when the average hand/forearm dermal absorption from humans is applied to Outdoor Residential Exposure Task Force (ORETF) worker exposure monitoring data (applicator dermal passive dosimetry measurements; unpublished data, PMRA, 2001a), the results are consistent with the Pest Control Operator (PCO) biomonitoring studies (2.8 lg/kg bw, Yeary, 1986; 2.0 lg/kg bw, Solomon et al, 1993;and 5.2 lg/ kg bw, Harris et al, 2002), again supporting the validity of the human dermal absorption data collected in the laboratory. Using Eq.…”

Review of 2,4-dichlorophenoxyacetic acid (2,4-D) biomonitoring and epidemiology

“…The highest levels in another turf study were observed during the spring season, compared to the summer and fall (Harris et al, 2010). Other exposure studies of professional turf applicators reported internal dose estimates and are not directly comparable to the studies in Table 3 (Harris et al, 2002, 2005). However, modeling of the variation of exposure in these reports confirmed that doses were Influenced by type of spray nozzle and use of gloves whereas job title alone was a poor determinant.…”

Dermal Exposure Associated with Occupational End Use of Pesticides and the Role of Protective Measures

“…Hand spraying with wide-area spray nozzles is associated with greater operator exposure than narrowly focused spray nozzles [31]. When pesticides are applied using tractors, spraying equipment mounted directly on the tractor is associated with a higher degree operator exposure than when the spray equipment is attached to a trailer [3].…”