ペットにノミ取り薬を塗った後、飼い主が手を洗うことが英国の河川を汚染している(Pet owners washing their hands after applying flea treatment to pets is polluting UK rivers)

2024-02-02

2024-02-01 サセックス大学

◆サセックス大学とインペリアル・カレッジ・ロンドンの研究者は、ペットの駆虫剤使用者がペットに塗布後28日以上も有毒な農薬（フィプロニルやイミダクロプリド）を手に付着させ、手を洗うことでこれらの農薬が排水に流れ込み、河川の汚染源となっていることを発表しました。
◆これらの農薬はペット駆虫剤で広く使用されており、有毒性が高いため深刻な懸念が示されています。研究者は規制と処方慣行の見直しを求め、ペット駆虫剤が河川への影響を考慮せずに承認されていることに対処する必要性を強調しています。

＜関連情報＞

犬へのスポットオン寄生虫駆除剤として散布されたフィプロニルとイミダクロプリドの排水経路：水生汚染の推定 Down-the-drain pathways for fipronil and imidacloprid applied as spot-on parasiticides to dogs: Estimating aquatic pollution

Rosemary Perkins, Leon Barron, Gaëtan Glauser, Martin Whitehead, Guy Woodward, Dave Goulson
Science of The Total Environment Available online:18 January 2024
DOI:https://doi.org/10.1016/j.scitotenv.2024.170175

Highlights

•Wastewater a major entry pathway for fipronil and imidacloprid to UK surface water
•Bathing, bed and handwash emissions from spot-on treated dogs were quantified.
•These pathways account for an estimated 20–40 % of measured wastewater pollution.
•Pet parasiticides are a major source of down-the-drain emissions.
•A systematic review of regulatory and prescribing practices is recommended.

Abstract

Fipronil and imidacloprid have been widely detected in UK surface waters in recent years, often at concentrations that ecotoxicological studies have shown can harm aquatic life. Down-the-drain (DTD) passage of pet flea and tick treatments are being implicated as an important source, with many of the UK’s 22 million cats and dogs receiving routine, year-round preventative doses containing these parasiticides. The UK Water Industry’s 3rd Chemical Investigation Programme (UKWIR CIP3) has confirmed wastewater as a major entry pathway for these chemicals into surface waters, but the routes by which they enter the wastewater system remain unclear. We addressed this knowledge gap by conducting the first quantification of DTD emissions from 98 dogs treated with spot-on ectoparasiticides containing fipronil or imidacloprid, through bathing, bed washing and washing of owners’ hands. Both chemicals were detected in 100 % of washoff samples, with bathing accounting for the largest emissions per event (up to 16.8 % of applied imidacloprid and 24.5 % of applied fipronil). Modelled to account for the frequency of emitting activities, owner handwashing was identified as the largest source of DTD emissions from the population overall, with handwash emissions occurring for at least 28 days following product application and an estimated 4.9 % of imidacloprid and 3.1 % of fipronil applied in dog spot-ons passing down-the-drain via this route. The normalised daily per capita emissions for all routes combined were 8.7 μg/person/day for imidacloprid and 2.1 μg/person/day for fipronil, equivalent to 20–40 % of the daily per capita load in wastewater, as estimated from UKWIR CIP3 data. Within the current international regulatory framework adhered to by the UK, the environmental exposure of veterinary medicines intended for use in small companion animals is assumed to be low, and DTD pathways are not considered. We recommend a systematic review of regulations and practices to address this overlooked pollution pathway.