Abstract:
Developed to replace organophosphate and carbamate insecticides, neonicotinoids are structurally similar to nicotine. The three main neonicotinoid insecticides, imidacloprid, clothianidin, and thiamethoxam, are being re-evaluated by Health Canada\'s Pest Management Regulatory Agency (PMRA). An important aspect of the re-evaluation is the potential for effects in non-target organisms, including aquatic organisms. Leaching into surface waters is one of the major concerns surrounding extensive use of neonicotinoids, especially in close proximity to water bodies. The PMRA has classified IMI as \'persistent\' with a \'high\' leaching potential. Globally, neonicotinoids have been detected in a variety of water bodies, typically at concentrations in the low μg/L range. While IMI has been included in some monitoring exercises, there are currently very few published data for the presence of CLO and THM in Canadian water bodies. The majority of neonicotinoid toxicity studies have been conducted with IMI due to its longer presence on the market and high prevalence of use. Aquatic insects are particularly vulnerable to neonicotinoids and chronic toxicity has been observed at concentrations of IMI below 1 μg/L. Acute toxicity has been reported at concentrations below 20 μg/L for the most sensitive species, including Hyalella azteca, ostracods, and Chironomus riparius. Fish, algae, amphibians, and molluscs are relatively insensitive to IMI. However, the biological effects of THM and CLO have not been as well explored. The Canadian interim water quality guideline for IMI is 0.23 μg/L, but there is currently insufficient use, fate, and toxicological information available to establish guidelines for CLO and THM. Based on concentrations of neonicotinoids reported in surface waters in Canada and globally, there is potential for aquatic invertebrates to be negatively impacted by neonicotinoids. Therefore, it is necessary to address knowledge gaps to inform decisions around guidelines and registration status for neonicotinoid insecticides in Canada to protect our aquatic ecosystems.
摘要:
开发用于替代有机磷酸酯和氨基甲酸酯类杀虫剂,新烟碱的结构与尼古丁相似。三种主要的新烟碱类杀虫剂,吡虫啉,clothianidin,和噻虫嗪,正在由加拿大卫生部的害虫管理监管机构(PMRA)重新评估。重新评估的一个重要方面是非目标生物的潜在影响,包括水生生物。浸出地表水是围绕新烟碱类广泛使用的主要问题之一,特别是在靠近水体的地方。PMRA已将IMI分类为具有“高”浸出潜力的“持久性”。全球范围内,已经在各种水体中检测到新烟碱,通常在低μg/L范围内的浓度。虽然IMI已经被包括在一些监测活动中,目前很少有关于加拿大水体中存在CLO和THM的公开数据。由于IMI在市场上的存在时间更长,并且使用率很高,因此大多数新烟碱毒性研究都是使用IMI进行的。水生昆虫特别容易受到新烟碱的影响,并且在IMI浓度低于1μg/L时观察到了慢性毒性。据报道,对于最敏感的物种,浓度低于20μg/L的急性毒性,包括Hyalellaazteca,ostracods,还有Chironomusriparius.鱼,藻类,两栖动物,软体动物对IMI相对不敏感。然而,THM和CLO的生物学效应还没有得到很好的探索。加拿大的IMI临时水质准则为0.23μg/L,但是目前使用不足,命运,以及可用于建立CLO和THM指南的毒理学信息。根据加拿大和全球地表水中报告的新烟碱的浓度,水生无脊椎动物有可能受到新烟碱类的负面影响。因此,有必要解决知识空白,为加拿大新烟碱类杀虫剂的指南和注册状态做出决定,以保护我们的水生生态系统。