Risa Hamada1, Yuko Ueda1, Keiko Wada2, Isao Saito1, Hiroshi Nomura1, Michihiro Kamijima3, Kunihiko Nakane4, Chisato Nagata2, Takaaki Kondo1, Jun Ueyama5. 1. Department of Pathophysiological Laboratory Sciences, Field of Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine, 1-1-20 Daiko-minami, Higashi-ku, Nagoya, 461-8673, Japan. 2. Department of Epidemiology and Preventive Medicine, Gifu University Graduate School of Medicine, 1-1 Yanagido, Gifu, 444-0014, Japan. 3. Department of Occupational and Environmental Health, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya, 467-8601, Japan. 4. Okazaki City Public Health Center, Okazaki-city, Aichi, 444-0014, Japan. 5. Department of Pathophysiological Laboratory Sciences, Field of Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine, 1-1-20 Daiko-minami, Higashi-ku, Nagoya, 461-8673, Japan. Electronic address: ueyama@met.nagoya-u.ac.jp.
Abstract
BACKGROUND AND AIM: Metofluthrin, profluthrin, tefluthrin, and transfluthrin are pyrethroid (PYR) insecticides increasingly used to control mosquitoes, flies, and moths in households and public places (hygiene-PYRs). Currently, there is limited data available concerning exposure to these novel hygiene-PYRs. The goal of this study was to monitor exposure to these hygiene-PYRs by analysing their urinary metabolites and to investigate the temporal and seasonal trends in the concentrations of these metabolites. METHODS: First morning urine samples were obtained from 50 Japanese children (four-six years old) in October of 2006, 2011, and 2015 (total = 150 children) in order to investigate temporal trends. Additionally, first-morning urine samples were collected from 44 three-year-old children in August-September of 2012 (summer) and in February of 2013 (winter) to investigate seasonal differences. The urinary concentrations of 2,3,5,6-tetrafluorobenzyl alcohol (FB-Al; a specific metabolite of transfluthrin), 4-methyl-2,3,5,6-tetrafluorobenzyl alcohol (CH3-FB-Al; a common metabolite of tefluthrin and profluthrin), 4-methoxymethyl-2,3,5,6-tetrafluorobenzyl alcohol (CH3OCH2-FB-Al; a specific metabolite of metofluthrin), and 2,3,5,6-tetrafluoro-1,4-benzenedimethanol (HOCH2-FB-Al; a common metabolite of metofluthrin, tefluthrin, and profluthrin) were measured using GC-MS/MS. RESULTS: For the investigated years, rapid increases in the detection rates of the hygiene-PYR metabolites were observed. In 2015, FB-Al was identified in 64% of the samples, CH3-FB-Al in 46%, CH3OCH2-FB-Al in 50%, and HOCH2-FB-Al in 83%. Significant increasing trends were found for the concentrations of all hygiene-PYR metabolites from 2006 to 2015 (Jonckheere-Terpstra test, p < 0.001). The concentrations of FB-Al and CH3OCH2-FB-Al were higher in summer than in winter (Mann Whitney-U test, p < 0.05). CONCLUSIONS: These findings suggest that, in Japanese children, exposure to hygiene-PYRs has increased over the past decade, and that children are exposed to higher levels of hygiene-PYRs in summer than in winter.
BACKGROUND AND AIM: Metofluthrin, profluthrin, tefluthrin, and transfluthrin are pyrethroid (PYR) insecticides increasingly used to control mosquitoes, flies, and moths in households and public places (hygiene-PYRs). Currently, there is limited data available concerning exposure to these novel hygiene-PYRs. The goal of this study was to monitor exposure to these hygiene-PYRs by analysing their urinary metabolites and to investigate the temporal and seasonal trends in the concentrations of these metabolites. METHODS: First morning urine samples were obtained from 50 Japanese children (four-six years old) in October of 2006, 2011, and 2015 (total = 150 children) in order to investigate temporal trends. Additionally, first-morning urine samples were collected from 44 three-year-old children in August-September of 2012 (summer) and in February of 2013 (winter) to investigate seasonal differences. The urinary concentrations of 2,3,5,6-tetrafluorobenzyl alcohol (FB-Al; a specific metabolite of transfluthrin), 4-methyl-2,3,5,6-tetrafluorobenzyl alcohol (CH3-FB-Al; a common metabolite of tefluthrin and profluthrin), 4-methoxymethyl-2,3,5,6-tetrafluorobenzyl alcohol (CH3OCH2-FB-Al; a specific metabolite of metofluthrin), and 2,3,5,6-tetrafluoro-1,4-benzenedimethanol (HOCH2-FB-Al; a common metabolite of metofluthrin, tefluthrin, and profluthrin) were measured using GC-MS/MS. RESULTS: For the investigated years, rapid increases in the detection rates of the hygiene-PYR metabolites were observed. In 2015, FB-Al was identified in 64% of the samples, CH3-FB-Al in 46%, CH3OCH2-FB-Al in 50%, and HOCH2-FB-Al in 83%. Significant increasing trends were found for the concentrations of all hygiene-PYR metabolites from 2006 to 2015 (Jonckheere-Terpstra test, p < 0.001). The concentrations of FB-Al and CH3OCH2-FB-Al were higher in summer than in winter (Mann Whitney-U test, p < 0.05). CONCLUSIONS: These findings suggest that, in Japanese children, exposure to hygiene-PYRs has increased over the past decade, and that children are exposed to higher levels of hygiene-PYRs in summer than in winter.