Assessment of tropical suburban surface soils contamination from Jengka,Malaysia

Heavy metals in suburban soils pose both indirect and direct health risks. This study assessed the concentrations of Cr, Zn, Pb, and Cd in Jengka (Malaysia) suburban soil and estimated the human health risk. Health risk assessment (HRA) was utilized to assess non-cancer and cancer risks. The concentrations of heavy metals increased in the following order: Cd < Zn < Cr < Pb. The heavy metals were found to be divided into two components using principal component analysis (PCA), with PC1 comprising Pb and Cd and PC2 containing Zn and Cr. PC1 originates from anthropogenic sources, while PC2 is often from mixed anthropogenic and natural sources. Despite having the lowest mean concentration, Cd was enriched based on the geo-accumulation index (Igeo) and enrichment factor (EF). Average hazard index values were below the acceptable threshold (HI < 1) for dermal and inhalation pathways suggesting a low non-cancer risk. Jengka suburban soil had total lifetime cancer risk values slightly higher than the acceptable threshold (1 × 10⁻⁵). Skin contact was the most prominent contributing exposure pathway for both non-carcinogenic and carcinogenic risks. This study suggests that heavy metal bioactivity levels be used to make a plausible HRA of heavy metal pollution in suburban soils.     

典型地区大气新型卤代阻燃剂污染特征、来源分析及人体暴露

利用大流量主动采样器采集了广州市天河区（23°08''56" N,113°21''30" E）和五指山国家自然保护区（18°54''02" N,109°41''24" E）两个典型地区的大气气相和颗粒相样品,测定了8种新型卤代阻燃剂（new halogenated flame retardants,NHFRs）的浓度,包括syn-DP、anti-DP、TBPH、PBEB、HBB、TBE、TBB、DBDPE.结果表明,广州大气中∑NHFRs平均浓度（335 pg·m^-3）远高于五指山（90.6 pg·m^-3）.广州大气中DBDPE为优势单体,占比为66.9%;五指山大气中NHFRs则以TBPH为主（65.8%）.季节变化上,广州的∑NHFRs浓度呈现一定季节变化,而五指山的∑NHFRs无明显季节变化,这可能与两地NHFRs的来源不同有关.结合主成分分析、风向频率和后向轨迹模型分析,发现两地阻燃剂来源有较大的差异：广州大气中NHFRs可能主要来源于电子垃圾拆解、工业输入和消费品的再挥发,而五指山大气中阻燃剂可能以外源输入为主.健康风险评价结果显示,我国大型城市大气中高浓度NHFRs的持续暴露会对城市居民健康特别是婴儿健康造成潜在危害.     

北京市某垃圾焚烧厂周边大气二(口恶)英污染特征及暴露风险

2014年4月至2015年1月对北京市某生活垃圾焚烧发电厂周边6 km范围内7个采样点采集环境空气,应用高分辨气相色谱-高分辨质谱（HRGC-HRMS）联用技术对二英（PCDD/Fs）浓度水平进行监测并对其组成特征及时空特征进行了分析.结果表明该生活垃圾焚烧发电厂周边环境空气中PCDD/Fs质量浓度的变化范围为8.9~140 pg·m^-3,毒性当量（TEQ）变化范围为0.11~1.8 pg·m^-3,其中秋季霾天4个采样点和冬季全部采样点超出日本环境空气质量标准限值（TEQ：0.6 pg·m^-3）.1,2,3,4,6,7,8-HpCDF和OCDD是四季空气中PCDD/Fs质量浓度的主要贡献单体,年平均贡献率分别为20.5%和14.0%,而2,3,4,7,8-PeCDF是总TEQ贡献最大的单体,年平均贡献率为43.3%.空间分布特征表现为各采样点浓度水平与距污染源距离远近没有显著相关性;季节变化特征表现为冬季值显著高于其他季节,分析可能与冬季燃煤采暖及大气扩散条件差导致的大气颗粒物污染较重有关,与各季采样时段内大气PM₁₀和PM_2.5的平均浓度水平呈正相关相一致.样品中二英同族体及异构体分布指纹谱图与该焚烧设施排放烟气存在差别,主成分分析（PCA）源解析结论与指纹谱图特征分析结论一致.二英呼吸暴露剂量估算结果表明该区域人群呼吸暴露风险总体处于较为安全的水平[0.060~0.224 pg·（kg·d）^-1],但仍需关注大气颗粒物重污染天气发生时的呼吸暴露风险.     

NO2吸入诱导小鼠肺组织上皮细胞间质转化及单酰基甘油酯酶抑制的保护作用

通过二氧化氮(NO_2)动式吸入染毒模型,探讨其对小鼠肺组织上皮细胞间质转化(epithelial-mesenchymal transitions,EMT)的影响及单酰基甘油酯酶(MAGL)抑制在此过程中的保护作用.首先检测暴露后肺组织硝酸盐、亚硝酸盐的含量,并考察对EMT标志蛋白E-钙粘蛋白(E-cadherin)和α平滑肌肌动蛋白(α-SMA)表达水平的影响.其次,在MAGL抑制剂JZL~(-1)84预处理后再次进行小鼠NO_2动态吸入染毒,检测不同处理条件下前列腺素E2(PGE2)含量,并考察JZL~(-1)84对E-cadherin和α-SMA表达水平的影响.结果表明,NO_2吸入显著上调小鼠肺组织中硝酸盐和亚硝酸盐的含量,且使小鼠肺组织中E-cadherin表达明显降低,α-SMA表达显著升高,说明NO_2通过其体内代谢衍生物可诱导小鼠肺组织EMT发生.而MAGL抑制可显著降低NO_2诱导的小鼠肺组织中前列腺素E2(PGE2)含量升高,并缓解吸入暴露造成的E-cadherin表达下降和α-SMA表达量增加,抑制EMT过程.由此提示,NO_2吸入暴露可诱导小鼠肺组织EMT发生,而MAGL抑制通过调控PGE2水平对这一损伤效应具有保护作用.     

Health hazards from exposure to cobalt with special reference to carcinogenic,mutagenic and teratogenic effects†

Occupational exposure to cobalt‐containing dust may cause a severe type of pneumoconiosis as well as obstructive lung disease. Peroral exposure to cobalt chloride may under certain circumstances precipitate cardiomyopathy.

There are only a limited number of experimental studies available which deal with the carcinogenic, mutagenic and teratogenic effects of cobalt and its salts. Single or repeated injections of cobalt powder or cobalt chloride have been shown to induce malignant tumours at the site of injection in rats, but not in mice. In vitro studies have shown that cobalt chloride has mutagenic and teratogenic properties. There are no data available on cancer incidence among workers occupationally exposed to cobalt. Thus the possible role of cobalt in human carcinogenesis is still an open question.     

空气湿度对自吸过滤式口罩过滤性能的影响研究

口罩是阻止颗粒物进入人体的有效防护用品,其性能优劣直接影响着佩戴人员的健康与安全。采用国标建议的呼吸阻力实验装置与自制的过滤效率实验装置,对自吸过滤式KN90,KN95系列口罩的呼吸阻力与不同相对湿度下的分级过滤效率进行实验研究。结果表明:所研究的6种口罩的呼气阻力与吸气阻力值不仅满足国标要求,而且满足佩戴舒适性的要求;在同一风速下,气流相对湿度的增加,使2种口罩对粒径为1 μm以下颗粒物的过滤效率降低,对1 μm以上颗粒物的过滤效率没有影响。     

垃圾焚烧厂周边大气二噁英含量及变化特征——以北京某城市生活垃圾焚烧发电厂为例

2013年4月至2014年1月对北京市某生活垃圾焚烧厂周边4km范围内5个采样点环境空气中二噁英含量、组成特征及季节变化特征进行了分析.结果表明该垃圾焚烧厂周边环境空气中PCDD/Fs质量浓度的变化范围为8.3~115pg/m³,毒性当量(TEQ)变化范围为0.11~1.9pg I-TEQ/m³,其中秋季1个采样点和冬季全部采样点超出日本环境空气质量标准限值(0.6pg I-TEQ/m³).1,2,3,4,6,7,8-HpCDF和OCDF均是四季空气中PCDD/Fs质量浓度的主要贡献单体,而2,3,4,7,8-PeCDF是总TEQ贡献最大的单体.空间分布特征表现为近源点位(~400m)浓度水平较高而其他点位(>1000m)浓度水平与距污染源距离远近没有显著相关性;季节变化特征表现为冬季值显著高于其他季节,分析可能与冬季采暖及大气扩散条件差导致的大气整体污染较重有关.样品中二噁英同族体及异构体分布指纹谱图与焚烧设施排放烟气存在差别,主成分分析(PCA)源解析结论与指纹谱图特征分析结论一致,体现为多种污染源共同作用的影响.二噁英呼吸暴露剂量估算结果表明该区域人群呼吸暴露风险总体处于较为安全的水平(0.034~0.161pg I-TEQ/(kg·d)),但仍需关注大气重污染天气发生时的呼吸暴露风险.     

Low level inhalation experiments with four different cadmium compounds in rats†

This long‐term inhalation study was designed to describe the toxicity and the carcinogenic risk from Cd compounds because it had been shown from former long‐term inhalation studies that cadmium choloride induced primary lung tumors in Wistar rats. It was therefore logical to examine whether other cadmium compounds to which human beings are more frequently exposed have also carcinogenic potency. In a long‐term inhalation study cadmium aerosols consisting of cadmium chloride (CdCl₂), cadmium oxide (CdO) as dusts and fumes, cadmium sulfate (CdSO₄), cadmium sulfide (CdS) and a combination of cadmium oxide/zinc oxide were used. Wistar rats were continuously exposed in inhalation chambers for 18 months 22 hrs a day or for 40 hrs a week. The studies will be terminated at the mean survival life time of the species. The aerosols were generated by several different systems. The particles of the cadmium aerosols have the average mass medium diameters in the range from 0.2 to 0.5 μm.     

Recent advances in arsenic mutagenesis and carcinogenesis†

Arsenic is ubiquitously distributed in nature and is released into the environment through non‐ferrous smelting operations, generation of power from coal, and agriculture.

Epidemiological studies have shown that the incidences of epidermoid carcinomas of the skin and lungs, and of pre‐cancerous dermal keratoses are significantly increased in human subjects exposed to arsenic compounds by oral or respiratory routes. The negative results obtained on animals treated with arsenicals suggest strongly that this metal is probably a cocarcinogen.

The results of the short‐term tests suggest that the cocarcinogenic properties of arsenic could be related to its ability to inhibit DNA repair.     

环境健康风险评价中我国居民呼吸速率暴露参数研究

呼吸速率是人体暴露和健康风险评价中的关键性暴露参数之一,然而迄今为止鲜见我国进行的系统调查研究和分析总结,以及公开发布能够代表我国居民的呼吸速率参数的报道,而通常是以引用美国发布的参数为主,导致评价结果的误差并增加了不确定性. 采用呼吸速率的能量估算方法,根据我国2004年大规模的膳食能量调查数据,计算了各类人群的呼吸速率参数. 结果表明:我国男、女性居民长期暴露的呼吸速率为4.7～13.9 m3/d;20～45岁男、女性居民轻、中、重3种活动强度下的呼吸速率为13.5～16.7 m3/d;2～5和6～17岁的城市居民呼吸速率分别比农村居民高15.8%和12.4%,而18～45和45岁以上的农村居民的呼吸速率分别比城市居民高3.9%和7.6%,城市和农村居民的呼吸速率存在差异;各年龄段长期暴露的日均呼吸速率是静息通气量的1.1～1.3倍,与相关文献的报道相符;如果直接引用美国的呼吸速率参数,将会造成2.6%～30.9%的误差.