Department of Chemistry, Université de Montréal, Montréal, QC, Canada.
Department of Chemistry, Université de Montréal, Montréal, QC, Canada.
Sci Total Environ. 2024 Feb 20;912:168680. doi: 10.1016/j.scitotenv.2023.168680. Epub 2023 Nov 22.
A reconnaissance survey was undertaken to evaluate the occurrence and risks of 27 pharmaceuticals and metabolites in the St. Lawrence watershed. Surface water samples were collected over a five-year period (2017-2021) along a 700-km reach of the St. Lawrence River as well as 55 tributary rivers (overall N = 406 samples). Additionally, depth water samples and sediments were collected near a major wastewater effluent. Caffeine, diclofenac, and venlafaxine were the most recurrent substances (detection rates >80 %), and extremely high levels were found near a municipal effluent (e.g., ibuprofen (860 ng/L), hydroxyibuprofen (1800 ng/L) and caffeine (7200 ng/L)). Geographical mapping and statistical analyses indicated that the St. Lawrence River water mass after the Montreal City effluent was significantly more contaminated than the other water masses, and that contamination could extend up to 70 km further downstream. This phenomenon was repeatedly observed over the five years of sampling, confirming that this is not a random trend. A slight increase in contamination was also observed near Quebec City, but concentrations rapidly declined in the estuarine transition zone. Tributaries with the highest pharmaceutical levels (ΣPharmas ∼400-900 ng/L) included the Mascouche, Saint-Régis, and Bertrand rivers, all located in the densely populated Greater Montreal area. When flowrate was factored in, the top five tributaries in terms of mass load (ΣPharmas ∼200-2000 kg/year) were the Des Prairies, Saint-François, Richelieu, Ottawa, and Yamaska rivers. All samples met the Canadian Water Quality Guideline for carbamazepine. Despite the large dilution effect of the St. Lawrence River, a risk quotient approach based on freshwater PNEC values suggested that four compounds (caffeine, carbamazepine, diclofenac, and ibuprofen) could present intermediate to high risks for aquatic organisms in terms of chronic exposure.
一项勘查性调查旨在评估圣劳伦斯流域 27 种药物和代谢物的出现和风险。在五年期间（2017-2021 年），沿圣劳伦斯河 700 公里的河段以及 55 条支流（总共采集了 406 个样本）采集了地表水样本。此外，还在一个主要废水排放口附近采集了深水域水样和沉积物。咖啡因、双氯芬酸和文拉法辛是最常见的物质（检出率>80%），在一个市政污水排放口附近发现了极高的浓度（例如布洛芬（860ng/L）、羟基布洛芬（1800ng/L）和咖啡因（7200ng/L））。地理制图和统计分析表明，圣劳伦斯河在经过蒙特利尔市污水排放口后的水体明显比其他水体更受污染，污染可能会向下游延伸 70 公里。这种现象在五年的采样中反复出现，证实这不是一个随机趋势。在魁北克市附近也观察到了轻微的污染增加，但在河口过渡区浓度迅速下降。药物浓度最高的支流（ΣPharmas ∼400-900ng/L）包括马斯科什、圣雷吉斯和贝特朗河，这些河流都位于人口稠密的大蒙特利尔地区。当考虑到流量时，以质量负荷（ΣPharmas ∼200-2000kg/year）计的前五个支流是德普雷里、圣弗朗索瓦、里歇卢、渥太华和雅马哈萨河。所有样品均符合加拿大水质准则中卡马西平的标准。尽管圣劳伦斯河有很大的稀释作用，但基于淡水 PNEC 值的风险商数方法表明，对于慢性暴露，有四种化合物（咖啡因、卡马西平、双氯芬酸和布洛芬）可能对水生生物存在中至高风险。
