| 1 | Arsenic species in electronic cigarettes:Determination and potential health risk显示文摘Human exposure to contaminants from electronic cigarettes(e-cigarettes)and the associated health effects are poorly understood.There has been no report on the speciation of arsenic in e-liquid(solution used for e-cigarettes)and aerosols.We report here determination of arsenic species in e-liquids and aerosols generated from vaping the e-liquid.Seventeen e-liquid samples of major brands,purchased from local and online stores in Canada and China,were analyzed for arsenic species using high-performance liquid chromatography and inductively coupled plasma mass spectrometry.Aerosols condensed from vaping the eliquids were also analyzed and compared for arsenic species.Six arsenic species were detected,including inorganic arsenate(iAsⅤ),arsenite(iAsⅢ),monomethylarsonic acid(MMA),and three new arsenic species not reported previously.In e-liquids,iAsⅢwas detected in 59%,iAsⅤin 94%,and MMA in 47%of the samples.In the condensate of aerosols from vaping the e-liquids,iAsⅢwas detected in 100%,iAsv in 88%,and MMA in 13%of the samples.Inorganic arsenic species were predominant in e-liquids and aerosols of e-cigarettes.The concentration of iAsⅢin the condensate of aerosols(median 3.27μg/kg)was significantly higher than that in the e-liquid(median 1.08μg/kg)samples.The concentration of inorganic arsenic in the vaping air was approximately 3.4μg/m3,which approaches to the permissible exposure limit(10μg/m3)set by the United States Occupational Safety and Health Administration(OSHA).According to the Environmental Protection Agency’s unit risk factor(4.3×10-3 perμg/m3)for inhalation exposure to inorganic arsenic in the air,the estimated excess lung cancer risk from lifetime exposure to inorganic arsenic in the ecigarette vaping air(3.4μg/m3),assuming e-cigarette vaping at 1%of the time,is as high as1.5×10-4.These results raise health concerns over the exposure to arsenic from electronic cigarettes. | Qingqing Liu Chengzhi Huang XChris Le | 2020 | Journal of Environmental Sciences2020，32，5： | 2 |
| 2 | Quantification and Differentiation of SARS-CoV‑2 Variants in Wastewater for Surveillance显示文摘Wastewater surveillance plays an important role in the monitoring of infections of SARS-CoV-2 at the community level.We report here the determination of SARS-CoV-2 and differentiation of its variants of concern in 294 wastewater samples collected from two major Canadian cities from May 2021 to March 2023.The overall method of analysis involved extraction of the virus and viral components using electronegative membranes,in situ stabilization and concentration of the viral RNA onto magnetic beads,and direct analysis of the viral RNA on the magnetic beads.Multiplex reverse transcription quantitative polymerase chain reaction(RT-qPCR)assays,targeting specific and naturally selected mutations in SARS-CoV-2,enabled detection and differentiation of the Alpha,Beta,Gamma,Delta,and Omicron variants.An Omicron triplex RT-qPCR assay targeting three mutations,HV 69−70 deletion,K417N,and L452R,was able to detect and differentiate the Omicron BA.1/BA.3,BA.2/XBB,and BA.4/5.This assay had efficiencies of 90−104%for all three mutation targets and a limit of detection of 28 RNA copies per reaction.Analyses of 294 wastewater samples collected over a two-year span showed the concentrations and trends of Alpha,Beta,Gamma,Delta,and Omicron variants as they emerge in two major Canadian cities participating in the wastewater surveillance program.The trends of specific variants were consistent with clinical reports for the same period.At the beginning of each wave,the corresponding variants were detectable in wastewater.For example,RNA concentrations of the BA.2 variant were as high as 10^(4)copies per 100 mL of wastewater collected in January 2022,when approximately only 50−60 clinical cases of BA.2 infection were reported in Canada.These results show that the strategy and highly sensitive assays for the variants of concern in wastewater are potentially useful for the detection of newly emerging SARS-CoV-2 variants and other viruses for future community biomonitoring. | Teresa Kumblathan Yanming Liu Xiaoli Pang Steve E.Hrudey XChris Le Xing-Fang Li | 2023 | Environment & Health2023，1，3： | 0 |
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