For lifetime non-smokers, lung cancer risk is mainly associated with inhalation exposure to air pollution. For the Chinese population, indoor air pollution due to solid fuel combustion has been the primary source of i...For lifetime non-smokers, lung cancer risk is mainly associated with inhalation exposure to air pollution. For the Chinese population, indoor air pollution due to solid fuel combustion has been the primary source of inhalation exposure for decades. Polycyclic aromatic hydrocarbons （PAHs） are the by-products of incomplete combustion.展开更多
This study determined the concentrations and inhalation bioaccessibility of cadmium, chromium, nickel and zinc in some foreign and locally available tobacco snuff and leaves. For the determination of the heavy metals ...This study determined the concentrations and inhalation bioaccessibility of cadmium, chromium, nickel and zinc in some foreign and locally available tobacco snuff and leaves. For the determination of the heavy metals concentration, the samples were ashed and washed with hydrochloric acid according to standard method. The bioaccessibility test employed the Stimulated Epithelial Lung Fluid (SELF). The total concentration of heavy metals in the four samples investigated ranged between 9.7 - 14.9 μg/g, 24.1 - 37.0 μg/g, 41 - 69 μg/g and 153 - 183 μg/g for cadmium, chromium, nickel and zinc respectively. The percentage inhalation bioaccessibility fraction of the four samples investigated ranged between 20.8% - 59.8%, 3.3% - 8.1%, 21.7% - 48.8% and 7.6% - 12.5% for cadmium, chromium, nickel, and zinc respectively. Statistical analyses using SPSS 21, revealed significant differences in the total concentration of heavy metals in the samples investigated except for Zinc. Risk assessment based on daily consumption of 10 g of the tobacco snuff employing total concentration of the heavy metals suggests that excluding nickel, all other metals investigated indicated daily intake values above WHO permissible levels. However, with the bioaccessible fractions, only cadmium, a known carcinogen indicated levels above WHO limits. From the results of this study, it can be deduced that consumption of tobacco snuff may induce negative health effects such as cancer and its attendant complications, the risk analysis based on bioaccessible concentration suggests lower health risk than analysis based on total heavy metal concentration;hence the assumption that snuff is a safe alternative to tobacco smoking may be erroneous.展开更多
Objective:To assess the excess lifetime cancer risk and lung cancer risk due to exposure to ^(222)Rn at homes,stone cutting and processing plants,and stone mines.Methods:^(222)Rn concentration was measured in 74 sampl...Objective:To assess the excess lifetime cancer risk and lung cancer risk due to exposure to ^(222)Rn at homes,stone cutting and processing plants,and stone mines.Methods:^(222)Rn concentration was measured in 74 sample sites.Sampling was conducted using Alpha Track,comprising CR-39 polymer film.The detectors were placed at the height of 1.00–1.50 m from the floor and away from windows and sunlight per the US.EPA guidelines.The detectors were retrieved after being exposed to ^(222)Rn for the period of three months and then etched in a 6.25 mol/L NaOH solution at 90C for 4 h.The results were used to assess the excess lifetime cancer risk(ELCR)and lung cancer risk(LCR).Results:The findings showed that the ELCR at homes,stone cutting and processing plants,and stone mines for the mean levels of ^(222)Rn were 0.49%,0.15%,and 0.15%,respectively.The ELCR values for all sampling sites were lower than the U.S.EPA action level.The number of lung cancer cases in the Neyriz due to the effective dose received by residents for the mean,maximum,and 95^(th) percentile was estimated to be 1.6,3.6,and 3.1 per year,respectively.The number of lung cancer cases per 106 population due to exposure to mean concentration for stone cutting and processing plants was 10.53,15.79,and 14.49,respectively.These values for stone mines were 10.39,26.76,and 18.87,respectively.The results have shown that LCR values were below the range recommended by ICRP.Conclusions:Overall,the ELCR,because of long-term exposure to ^(222)Rn and its progeny levels,does not pose a significant threat to residents and workers.The LCR associated with radon exposure was low in three sampling sites that could be considered safe for both residents and workers.展开更多
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-ciga...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.展开更多
基金funded by the National Natural Science Foundation of China(41390240 and 41571130010)the 111 Project(B14001)
文摘For lifetime non-smokers, lung cancer risk is mainly associated with inhalation exposure to air pollution. For the Chinese population, indoor air pollution due to solid fuel combustion has been the primary source of inhalation exposure for decades. Polycyclic aromatic hydrocarbons （PAHs） are the by-products of incomplete combustion.
文摘This study determined the concentrations and inhalation bioaccessibility of cadmium, chromium, nickel and zinc in some foreign and locally available tobacco snuff and leaves. For the determination of the heavy metals concentration, the samples were ashed and washed with hydrochloric acid according to standard method. The bioaccessibility test employed the Stimulated Epithelial Lung Fluid (SELF). The total concentration of heavy metals in the four samples investigated ranged between 9.7 - 14.9 μg/g, 24.1 - 37.0 μg/g, 41 - 69 μg/g and 153 - 183 μg/g for cadmium, chromium, nickel and zinc respectively. The percentage inhalation bioaccessibility fraction of the four samples investigated ranged between 20.8% - 59.8%, 3.3% - 8.1%, 21.7% - 48.8% and 7.6% - 12.5% for cadmium, chromium, nickel, and zinc respectively. Statistical analyses using SPSS 21, revealed significant differences in the total concentration of heavy metals in the samples investigated except for Zinc. Risk assessment based on daily consumption of 10 g of the tobacco snuff employing total concentration of the heavy metals suggests that excluding nickel, all other metals investigated indicated daily intake values above WHO permissible levels. However, with the bioaccessible fractions, only cadmium, a known carcinogen indicated levels above WHO limits. From the results of this study, it can be deduced that consumption of tobacco snuff may induce negative health effects such as cancer and its attendant complications, the risk analysis based on bioaccessible concentration suggests lower health risk than analysis based on total heavy metal concentration;hence the assumption that snuff is a safe alternative to tobacco smoking may be erroneous.
文摘Objective:To assess the excess lifetime cancer risk and lung cancer risk due to exposure to ^(222)Rn at homes,stone cutting and processing plants,and stone mines.Methods:^(222)Rn concentration was measured in 74 sample sites.Sampling was conducted using Alpha Track,comprising CR-39 polymer film.The detectors were placed at the height of 1.00–1.50 m from the floor and away from windows and sunlight per the US.EPA guidelines.The detectors were retrieved after being exposed to ^(222)Rn for the period of three months and then etched in a 6.25 mol/L NaOH solution at 90C for 4 h.The results were used to assess the excess lifetime cancer risk(ELCR)and lung cancer risk(LCR).Results:The findings showed that the ELCR at homes,stone cutting and processing plants,and stone mines for the mean levels of ^(222)Rn were 0.49%,0.15%,and 0.15%,respectively.The ELCR values for all sampling sites were lower than the U.S.EPA action level.The number of lung cancer cases in the Neyriz due to the effective dose received by residents for the mean,maximum,and 95^(th) percentile was estimated to be 1.6,3.6,and 3.1 per year,respectively.The number of lung cancer cases per 106 population due to exposure to mean concentration for stone cutting and processing plants was 10.53,15.79,and 14.49,respectively.These values for stone mines were 10.39,26.76,and 18.87,respectively.The results have shown that LCR values were below the range recommended by ICRP.Conclusions:Overall,the ELCR,because of long-term exposure to ^(222)Rn and its progeny levels,does not pose a significant threat to residents and workers.The LCR associated with radon exposure was low in three sampling sites that could be considered safe for both residents and workers.
基金supported by National Natural Science Foundation of China(Nos.21535006,21906130)Southwest University Postdoctoral Science Foundation(Nos.5330600027,5330600094)+2 种基金the Natural Sciences and Engineering Research Council of Canadathe Canadian Institutes of Health Research,Alberta InnovatesAlberta Health
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.
