树脂分离-原子吸收法测定涉水产品及饮用水中六价铬

目的:建立石墨炉原子吸收法测定涉水产品及饮用水中六价铬含量。方法:采用强酸性阳离子树脂柱对样品进行前处理,并以磷酸二氢铵为基体改进剂,采用石墨炉原子吸收测定六价铬含量。结果:强酸性阳离子树脂柱可有效去除三价铬及其它共存离子,10 g/L磷酸二氢铵可使测定的精密度和稳定性得到改善,并减少基体干扰。铬浓度在0~10.00μg/L范围内,回归方程为Y=0.0539X 0.006,r=0.9993,具有良好的线性关系;方法的检出限为0.02μg/L,相对标准偏差为2.84%~7.14%,方法回收率为89%~108%,该法与国标化学法结果对比无显著性差异。结论:方法精密准确,快捷灵敏,抗干扰能力强,便于推广。     

Cancer mortality in a Chinese population exposed to hexavalent chromium in drinking water

BACKGROUND: In 1987, investigators in Liaoning Province, China, reported that mortality rates for all cancer, stomach cancer, and lung cancer in 1970-1978 were higher in villages with hexavalent chromium (Cr+6)-contaminated drinking water than in the general population. The investigators reported rates, but did not report statistical measures of association or precision. METHODS: Using reports and other communications from investigators at the local Jinzhou Health and Anti-Epidemic Station, we obtained data on Cr+6 contamination of groundwater and cancer mortality in 9 study regions near a ferrochromium factory. We estimated: (1) person-years at risk in the study regions, based on census and population growth rate data, (2) mortality counts, based on estimated person-years at risk and previously reported mortality rates, and (3) rate ratios and 95% confidence intervals. RESULTS: The all-cancer mortality rate in the combined 5 study regions with Cr+6-contaminated water was negligibly elevated in comparison with the rate in the 4 combined study regions without contaminated water (rate ratio = 1.13; 95% confidence interval = 0.86-1.46), but was somewhat more elevated in comparison with the whole province (1.23; 0.97-1.53). Stomach cancer mortality in the regions with contaminated water was more substantially elevated in comparison with the regions without contaminated water (1.82; 1.11-2.91) and the whole province (1.69; 1.12-2.44). Lung cancer mortality was slightly elevated in comparison with the unexposed study regions (1.15; 0.62-2.07), and more strongly elevated in comparison with the whole province (1.78; 1.03-2.87). Mortality from other cancers combined was not elevated in comparison with either the unexposed study regions (0.86; 0.53-1.36) or the whole province (0.92; 0.58-1.38). CONCLUSIONS: While these data are limited, they are consistent with increased stomach cancer risk in a population exposed to Crz=6 in drinking water.     

二苯碳酰二肼分光光度法测定饮用水中六价铬的改进探讨

目的改进生活饮用水中六价铬的检测方法(二苯碳酰二肼分光光度法),消除二价铁对检测的干扰。方法对生活饮用水标准检验方法 GB/T5750.6-2006 10.1二苯碳酰二肼分光光度法(原法)测定水中六价铬的方法进行了适当的改进,检测前将水样pH值调至弱碱性,改变试剂的加入顺序,测定时先加二苯碳酰二肼和六价铬生成比较稳定的络合物,再加酸调节pH值以消除二价铁离子的干扰。结果方法曲线在0.004μg/mL～0.2μg/mL有良好的线性关系,r=0.999 5,最低检测质量浓度0.004 mg/L,回收率为96.0%～104.0%,相对标准偏差为0.4%。结论实验结果可靠,本改进方法可消除二价铁对分光光度法测定饮用水中六价铬的干扰。     

高效液相色谱法测定生活饮用水中的六价铬

目的 建立高效液相色谱法测定生活饮用水中六价铬的方法.方法 采用InoPacTM AS7为分析柱,InoPacTM AG7为保护柱,探究高效液相色谱法直接测定生活饮用水中的六价铬时,流动相、进样量的选择对结果的影响.结果 确定高效液相色谱法测定生活饮用水六价铬的最佳色谱条件,为波长375 nm,120 mmol/L硫酸...     

离子色谱法同时测定饮用水中三价铬与六价铬分析方法验证

目的:确认离子色谱法同时测定饮用水中三价铬((Cr3+)与六价铬(Cr6+)分析方法可靠、准确,达到检测要求。方法:通过对系统适用性、检测限和定量限、精密度、准确度、线性范围的考察,证明该方法适用于使用目的。结果:Cr3+浓度在0.20 mg/L～8.0 mg/L;Cr6+浓度在4.0×10-4 mg/L～0.40 mg/L范围内,具有良好的线性关系(r=0.9994;r=0.9998);方法检出限Cr3+和Cr6+分别为0.139 mg/L、0.304×10-3 mg/L;精密度RSD均小于5%,平均加标回收率为86.7%～101.6%。结论:该方法灵敏度高,重现性好,能满足同时测定饮用水中三价铬与六价铬的分析要求。     

饮水短期铬暴露对大鼠健康的影响

目的通过动物实验验证饮水中铬短期暴露的健康效应及分离点,计算其饮水短期暴露健康风险健康参考值(health advisory, HA),为饮水中铬短期暴露健康风险研究提供数据基础。方法选择SPF清洁级SD大鼠120只,雌雄各半,随机分为6组,以去离子水为阴性对照组,灌胃给予以铬计浓度为0、7.2、8.3、14.4、24.0和28.8 mg/(kg·d)的铬酸钾(potassium chromate,K_2CrO_4),染毒第14天和第28天进行血常规、血生化及组织病理学检测。实验结果采用单因素方差分析进行统计分析,P<0.05则认为差异有统计学意义。结果染毒28天后,各组雌性大鼠肝重均低于对照组,其中24.0、28.8 mg/(kg·d)组雌性大鼠肝重分别为(6.68±0.90)和(7.08±0.36) g,与对照组相比差异有统计学意义(P<0.05)。此时雄性大鼠24.0、28.8 mg/(kg·d)组谷丙转氨酶(alanine transaminase,ALT)分别为(59.04±10.98)及(63.78±5.89) U/L,明显高于对照组(P<0.05);同时其血中碱性磷酸酶(alkaline phosphatase,ALP)水平低于对照组,分别为(130.52±23.22)及(126.34±28.25) U/L,与对照组相比差异有统计学意义(P<0.05)。结论以大鼠肝损伤指标(肝重、ALT、ALP)作为健康效应指标,得到LOAEL值为24.0 mg/(kg·d),NOAEL值为14.4 mg/(kg·d),参考美国环境保护署(USEPA)制定HA值的计算方式,获得HA值为1.44 mg/L,该结果与USEPA所得结果一致。     

Reflections on hexavalent chromium: health hazards of an industrial heavyweight

Chromium has been used commercially in the United States for more than 100 years in metal alloys and other compounds, as a pigment, and in the tanning and metal plating industries, and many studies have looked at its effects in terms of occupational health. But, although scientists know that Cr(VI) is a human carcinogen and that it can cause other deleterious health effects including kidney and liver damage, certain questions remain about the metal's effects, such as which routes of exposures are dangerous for humans.     

A retrospective-cohort study of occupational exposure to hexavalent chromium

A retrospective cohort study was conducted to examine the risk of mortality, cancer, and other adverse health outcomes, at the United States' largest chromate chemicals manufacturing facility in Castle Hayne, North Carolina. This facility, built in 1971, was designed to reduce the high levels of chromium exposure found at most older facilities. Exposure assessment was based on analysis of more than 5,000 personal breathing zone samples collected over a 15-year period. A questionnaire was used to collect relevant occupational, medical, smoking, and other information from current and former employees. Analysis of the cohort's mortality experience found no substantial departures from that expected based on external comparisons, although evidence of a healthy worker effect was observed. Internal cohort analyses were limited by relatively small numbers; however, a subgroup of employees who transferred from older facilities was found to have higher risks of mortality (odds ratio = 1.27 for each 3 years of previous exposure; 90% confidence interval (CI) = 1.07–1.51) and cancer (odds ratio = 1.22 for each 3 years of previous exposure; 90% CI = 1.03–1.45). While this subgroup represented only 11% of the individuals in this study, they accounted for 46% (6/13) of all observed cancers (excluding skin cancers) and 60% (3/5) of lung cancers. There was no increased risk of mortality or cancer among employees who worked only at the newer facility. As an etiologic research study, the results are limited by the relatively small number of subjects and short follow-up; nevertheless, the findings can be used to design and implement a prospective surveillance system for monitoring the health of chromate production workers. © 1994 Wiley-Liss, Inc.     

Systematic review and quantification of respiratory cancer risk for occupational exposure to hexavalent chromium

Aim

To investigate the exposure-risk relationship for occupational chromium (VI) exposure and lung cancer in order to establish exposure limits.

Methods

We systematically searched for studies reporting on occupational Cr(VI) exposure and cancers of the respiratory tract. To be included, studies needed to provide data for more than one level of occupational Cr(VI) exposure, adequately consider the confounder smoking and be of adequate methodological quality. Because direct genotoxicity was considered the predominant mechanism of carcinogenesis of Cr(VI), linear models were applied in order to fit risk data. Relative risks were calculated based on these linear regression models and then used to estimate excess absolute risks.

Results

Five studies of two cohorts of chromium production workers in Baltimore, Maryland, and Painesville, Ohio, were included. Based on different estimates for the exposure effect, the absolute excess risk was found to be “acceptable” (less than 4 per 10,000 according to the German Committee on Hazardous Substances, “AGS”) at a Cr(VI) concentration of 0.1 μg/m³, and became “intolerable” (more than 4 per 1,000) beyond a Cr(VI) concentration of 1 μg/m³.

Conclusion

Occupational exposure limits for Cr(VI) based on excess absolute risks can be derived from published data identified by a systematic literature review.     

离子色谱–质谱法测定水质中六价铬的方法研究

目的:建立离子色谱分离、电喷雾质谱检测水质中六价铬的方法。方法:水样经0.22μm微孔滤膜过滤后直接进样,以20 mmol/L KOH溶液为流动相,IonPac AS21 Analytical 2×250 mm色谱柱分离六价铬,使用单四级杆质谱,选择离子模式检测,监测离子为m/z118、117、101、85,其中117为定量离子。结果:Cr(Ⅵ)的线性范围为0μg/L～100.0μg/L,方法的检测限为0.57μg/L。在空白水样中分别添加4.0μg/L、10.0μg/L、50.0μg/L的六价铬,测得平均回收率(n=6)依次为102%、101%、100%,相对标准偏差分别为1.27%、2.82%、1.63%。与分光光度法对照表明,其结果无显著性差异。结论:该方法操作简便,快速,准确度和灵敏度高。     

饮水型砷暴露对人群甲基化代谢能力的影响

目的探讨饮水型砷暴露对人群甲基化代谢能力的影响。方法以带有砷化物预处理装置的原子吸收分光光度计测定砷暴露人群及无砷暴露对照人群血、尿中无机砷(iAs)、甲基胂(MMA)、二甲基胂(DMA)含量。以iAs、MMA及DMA的总和表示总胂(tAs)水平;以(MMA+DMA)/tAs及DMA/(MMA+DMA)分别计算一甲基化率(PMI)和二甲基化率(SMI)水平。结果砷暴露人群血中iAs、MMA、DMA、tAs及PMI水平均显著高于相应对照人群的水平,而SMI水平显著低于对照人群。尿中MMA水平分别与血中PMI及SMI水平呈显著正相关(r=0.419,P<0.01)及负相关(r=-0.326,P<0.05)。暴露组和对照组血中各种砷化物水平及甲基化率水平在男女间差异无显著性。结论砷暴露人群与无砷暴露人群相比甲基化率有差异,PMI显著增高,SMI显著降低。人群甲基化率无显著性别差异。     

Association between manganese exposure through drinking water and infant mortality in Bangladesh

BACKGROUND: Manganese is a common natural contaminant of groundwater in Bangladesh. In this cross-sectional study we assessed the association between water manganese and all-cause infant mortality in the offspring of female participants in the Health Effects of Arsenic Longitudinal Study Cohort. METHODS: In 2001, drinking water samples were collected, a history of well use was obtained, and a history of birth outcomes was ascertained. To avoid misclassification of exposure, women were included only if they had been drinking from the same well for most of their childbearing years (marriage years - well years 相似文献   

Human exposure to trihalomethanes in drinking water]

Halogenated hydrocarbon compounds, some of them recognized as carcinogenic to different animal species can be found in drinking water. Chloroform, bromodichloromethane, dibromochloromethane and bromoform are the most important trihalomethanes found in potable water. They are produced in natural waters during chlorinated desinfection by the halogenation of precursors, specially humic and fulvic compounds. The review, in the MEDLINE covers the period from 1974 to 1998, presents the general aspects of the formation of trihalomethanes, sources of human exposure and their toxicological meaning for exposed organisms: toxicokinetic disposition and spectrum of toxic effects (carcinogenic, mutagenic and teratogenic).     

Public exposure to 226Ra in drinking water

This paper presents a new method for calculating the effective dose of 226Ra regularly ingested with drinking water over a long period of time. The method is based on the assessment of cumulated 226Ra activity in the fraction retained in the whole body at time t (in days) after intake [so called m(t) value]. For modelling, simulation, and visualisation of the continuous intake of 226Ra by drinking water, we used the Simulink program package integrated with the Matlab. The dose assessment was performed for 226Ra activities of 5 mBq L(-1), 50 mBq L(-1), 1000 mBq L(-1) and 5000 mBq L(-1). The results suggest that 226Ra activities above 1000 mBq L(-1) produce effective doses which are below the recommended maximum. However, the potential effect of 226Ra activities of this extent is still unknown in children.     

An environmental hazard assessment of low-level dermal exposure to hexavalent chromium in solution among chromium-sensitized volunteers

To evaluate the potential for elicitation of allergic contact dermatitis from contact with standing water in the environment, 26 persons known to be allergic to hexavalent chromium [Cr(VI)] were exposed to 25 to 29 mg/L Cr(VI) by immersion of one arm for 30 minutes per day on 3 consecutive days in a potassium dichromate bath. Sixteen of the 26 volunteers demonstrated either no or an equivocal response to the Cr(VI) challenge. Ten of the volunteers developed a few papules or vesicles (1 to approximately 15), mild redness, and pruritus on the Cr(VI)-challenged arm. Histopathological examination of the papules revealed spongiosis and perieccrine and perivascular inflammation. The responses were diagnosed as acute perieccrine reactions. It was concluded that exposure to similar concentrations of Cr(VI) in the environment does not pose an allergic contact dermatitis hazard, even to Cr-sensitized persons.     

Low-level hexavalent chromium exposure and rate of mortality among US chromate production employees

OBJECTIVE: Although numerous studies have reported an elevated lung cancer risk among chromium chemical production employees, few studies have focused on employees hired after major process changes and enhanced industrial hygiene controls were implemented. METHODS: This study examines the mortality experience of two post-change cohorts of chromate production employees constituting the current US chromium chemical industry. RESULTS: Mortality among chromium chemical workers generally was lower than expected on the basis of national and state-specific referent populations. Lung cancer mortality was 16% lower than expected, with only three lung cancer deaths (3.59 expected). CONCLUSION: The absence of an elevated lung cancer risk may be a favorable reflection of the post-change environment. However, longer follow-up allowing an appropriate latency for the entire cohort will be needed to confirm this conclusion.