Household insecticide use and urinary 3-phenoxybenzoic acid levels in an elder population: a repeated measures data

Jin Hee Kim,Yun-Chul Hong,Sungroul Kim

doi:10.1038/s41370-020-00276-3

Abstract

BackgroundPyrethroids are associated with adverse health consequences, even at low-dose exposures. However, there is limited evidence on pyrethroids exposure levels among vulnerable elder population and on their exposure sources.ObjectiveWe tried to determine pyrethroids exposure levels among Korean elders and their exposure sources.MethodsWe measured levels of 3-phenoxybenzoic acid (3-PBA), a pyrethroids metabolite, in urines repeatedly collected from 1239 Korean rural and urban elders; we also explored exposure sources for pyrethroids using questionnaire data.ResultsOur participants had high levels of 3-PBA with 446 (36.0%) of elders with 3-PBA level over 2 ng/mL of 95th percentile of the German representative populations. After adjustment for sex, age, smoking status, visit episode, and surveyed season using linear mixed effect models, household insecticide spray use was significantly associated with 3-PBA level (β = 0.03 and p = 0.02) and the association was apparent only for females (β = 0.03 and p = 0.03). In the analyses for nonlinear relationships using generalized additive mixed models, there was a J-shape change in 3-PBA level by insecticide spray use (p < 0.01 both in total population and in females).SignificanceHousehold insecticide spray was a predominant exposure source for pyrethroids at community level among Korean elders, warning more stringent control for frequently exposed environmental factors for pyrethroids including insecticide spray.

Highlights

Pyrethroids are synthetic analogues of natural insecticidal compounds present in the extracts of pyrethrum flowers
We found a strong nonlinear relationship for total elder population, showing a weak J-shape change of 3-phenoxybenzoic acid (3-PBA) level by insecticide spray use and no change in level by increase of insecticide spray use at the lower end of exposure; over a potential threshold, we found a strong increase in 3-PBA level by increase of insecticide spray use with statistical significance (p < 0.01) (Fig. 2)
Because 3-PBA levels were higher in general in female participants than in male participants of our study, we further evaluated the relationship between insecticide spray use and 3-PBA level by sex

Summary

Results

Our participants included 377 males and 862 females (Table 1). At the first visit, mean age of our participants was 75.3 years ranged from 60 to 98 years. Because of potential differences in insecticide exposure between males and females, by age, between rural and urban areas, by survey episode (because of survey duration related to season), and by surveyed season, we compared urinary 3-PBA levels by these population characteristics as well as by basic characteristics including BMI, smoking status, and drinking status. Male Female Age (year) 60–69 70–79 80–89 90–99 BMI (kg/m2)

Introduction

Methods

Conclusion

Compliance with ethical standards