Mutagenicity of various organic fractions of diesel exhaust particles

Treated with various organic fractions of Diesel Exhaust Particles (DEP), the Ames test withSalmonella typhimurium strains TA98 and TA100, and the mice micronucleus test were employed to study the mutagenic activity in the bacterial reverse mutation system, with and without a mammalian S₉ activation component, and the clastogenic activity in mice polychromatic erythrocyte (PCE) stem cells. Extracted ultrasonically with dichloromethane then using the acid and base separated reaction and column chromatography, DEP were divided into five organic fractions. They are the organic acid fraction (Fl), the organic base fraction (F2), the aliphatic hydrocarbon fraction (F3), the aromatic hydrocarbon fraction (F4) and the polar fraction (F5). Results showed that an increase in the counted numbers of histidine revertants on theSalmonella TA100 and TA98 was observed with or without (S₉ mix), but these activities were more pronounced in the TA98 strains especially in the absence of the S₉ mix. These results suggest that the organic fractions of DEP contain mainly compounds with direct frame-shift mutaganicity. Positive results were also obtained from mice micronucleus assay. The frequency of mice bone marrow micronucleated polychromatic erythrocytes (PCE) was increased using this assay and it showed a definite dose-response relationship. The results suggest that various organic fractions could affect spindle fiber function or formation in mammalian cells. Compared with the results of different organic fraction, the effects of the F2, F4 and F5 were found to be stronger than those of other fractions. Based on the findings obtaind in the Ames and micronucleus tests, DEPs have genotoxic effects in both of the test systems. The project was supported by the National Nature Science Foundation of China, No 39270576     

Mutagenicity of diesel exhaust particle extracts: Influence of non-petroleum fuel extenders

The mutagenicity of dichloromethane extracts of diesel participate exhaust, collected while the engine was running at steady state on diesel fuel alone was higher than when 10% ethanol, butanol, and a middle distillate fraction of SRC-II (a solvent refined coal liquid) were added to the fuel (Salmonella strains TA-98 and TA-100). Although the three fuel extenders decreased the specific mutagenicity of the extracts, they increased the amount of particle-associated organic material 2 to 4-fold, resulting in higher estimates of mutagenicity emitted from the exhaust than that calculated for diesel fuel alone. Small increases in total hydrocarbons and carbon monoxide emissions were measured when butanol and SRC-II were added. Particulate emissions were 15% lower for the three fuel extenders compared to diesel fuel alone. The results point to the need for further research using different engine types and simulated urban and highway driving cycles.     

Mutagenicity studies and D-glucaric acid determination in urine of workers exposed to mineral oils

Summary Urine from workers of a cold-rolling steel plant exposed to mineral oils were tested for the mutagenic activity by the Salmonella/microsome assay, and for D-glucaric acid content as a measure of hepatic mixed-function oxidase activity. An occupationally unexposed group served as control. The biological monitoring phase followed an environmental phase carried out in the working environment that showed a substantially low mutagenic/carcinogenic risk for the exposed workers. Urine samples were collected before, during and after work. From the results it was observed that the urinary mutagenicity was detectable only with TA98 strain in the presence of enzymatic activation (+ S9 mix). Further addition of beta-glucuronidase did not give any enhanced mutagenic effects. There was a significant difference in urinary mutagenicity between the exposed and control workers. However, in both groups the highest mutagenicity data was found in smokers: both exposed smoking workers and smoking controls had significantly higher urine mutagenicity than the non-smoking exposed and control workers. The results suggested a synergistic effect of smoking with exposure to mineral oils: the mutagenicity of urine from exposed smokers was significantly higher than that of control smokers. There was no difference in urinary D-glucaric acid results between exposed and unexposed groups, however, smokers of both groups had a significant increase in D-glucaric acid excretion. The authors suggest that even for this workplace with its low mutagenic/carcinogenic risk, smoking could interact with the complex mixtures present in the environment, and thus modify urinary mutagenicity data.     

大气颗粒提取物的致突变性

用五段分级采样器采集太原某焦化厂厂区大气颗粒物，用液相色谱测定不同粒径颗粒物上５种多环芳烃（ＰＡＨ）的含量，并用Ａｍｅｓ试验及ＣＨＬ细胞姐妹染色单体互换（ＳＣＥ）试验，观察不同粒径颗粒提取物的致突变性。结果表明５种ＰＡＨ浓度均很高，芘为１４．８９μｇ／１００ｍ３、为１９．３５μｇ／１００ｍ３、苯并（ａ）蒽（ＢａＡ）为１８．９μｇ／１００ｍ３、为１１４．６７μｇ／１００ｍ３、苯并（ａ）芘（ＢａＰ）为１５．９μｇ／１００ｍ３。４７～７０％的ＰＡＨ富集在≤２μｍ细颗粒上，其质量中值直径芘、、ＢａＡ、、ＢａＰ分别为２．２、２．１、１．６、１．９、１．３。Ａｍｅｓ试验和ＳＣＥ试验结果均表明，分级颗粒粒径愈小其提取物致突变作用愈强。     

Exposure to nitrogen oxides and other air pollutants from automobiles.

We have conducted an epidemiological study to investigate the association between exposure to automobile exhaust and respiratory health. Three zones were selected in Tokyo according to expected exposure levels. Zone A is within 20 meters from the roadside of major roads with heavy traffic. Zone B is 20-150 meters away from the roadside of the same road. Zone C is the residential district in a suburb of Tokyo. Zone A, which was nearest to the roads, had the highest mean levels of personal exposure to nitrogen dioxide for housewives, followed by Zone B and Zone C. Ambient levels of nitrogen oxides, and mass concentrations, polycyclic aromatic hydrocarbons and mutagenicity of suspended particulate matter were higher at the roadside within Zone A. A cross-sectional study of respiratory symptoms and repeated examinations of pulmonary function were also performed in each zone. These results suggest that exposure to automobile exhaust may be associated with respiratory symptoms. Nevertheless, pulmonary function didn't show consistent differences over all examinations. We should have further analyses about a decline of pulmonary function with age.     

Mutagenicity of urine from young male smokers and nonsmokers

Summary The mutagenicity of urine from a healthy population of young adult men (average age of 23 years), including 61 smokers and 107 nonsmokers, was investigated with the Salmonella/microsome test using the tester strain S. typhymurium TA98. In quantifying the assay, the use of dichloromethane was suitable for eluting the mutagenicity of smokers' urine from the XAD-2 resin column. We assayed mutagenicity in condensates of such dichloromethane eluates and found that the mutagenicity of smokers' urine was significantly higher than that of nonsmokers' urine. In the smokers' group, correlation coefficient between the mutagenicity of the urine and the actual number of cigarettes smoked on the day of urine collection or the average number of cigarettes smoked per day was statistically significant at 0.266 or 0.454, respectively. Our results suggest a correlation between the increase of mutagens in urine and smoking habits.     

Toxicological characteristics of refinery streams used to manufacture lubricating oils

In the past, reports on the tumorigenic potential of lubricating oils in experimental animals have poorly defined the materials under study. In this paper the results of mouse skin painting studies with 46 clearly defined samples of refinery streams associated with lubricating oil processing show that modern conventional solvent refining of distillates removes tumorigenic potential while conventional acid refining may not. Furthermore, dewaxing, hydrofinishing, and clay treatments do not appear to mitigate the tumorigenicity of the lubricant distillates. Lubricant processing has changed over the years and assessments of the carcinogenicity of present-day lubricating materials must be based on knowledge of modern processing.     

黑加仑提取物的致突变性和亚急性毒性研究

目的对黑加仑提取物的致突变性和亚急性毒性进行评价,为黑加仑提取物的进一步开发利用提供依据。方法设1.25、2.5和5.0g/kg体重3个剂量观察对小鼠骨髓细胞微核和小鼠精子畸形的影响。设0.625、1.25、2.5g/kg体重3个剂量,观察亚急性毒性。结果各剂量组各项指标均未见有明显的亚急性毒性。各剂量组对小鼠未见有明显的致突变性。结论在本实验条件下,黑加仑提取物无致突变性和亚急性毒性。     

New and existing oils and fats used in products with reduced trans-fatty acid content

The US Food and Drug Administration's final ruling on trans-fatty acid labeling issued in 2003 has caused a rapid transformation in the fat and oil industries. Novel ingredients and improved technologies are emerging to replace partially hydrogenated fats in foods. We present an overview of the structure and formation of trans fatty acids in foods, and a comprehensive review of the newly formulated products and current procedures practiced by the edible oil industry to reduce or eliminate trans fatty acids in response to the Food and Drug Administration's regulations mandating trans fat labeling of foods.     

PAH Content and Mutagenicity of Marine Sediments from the Venice Lagoon

Sediments from the Venice lagoon, a polluted coastal environment in northeastern Italy, were assayed for mutagenicity and content of several toxic microcontaminants, which included selected polycyclic aromatic hydrocarbons (PAHs); the latter are specifically dealt with in this paper. Samples were collected at three lagoon sites with reasonably distinct environmental features—urban, industrial, or agricultural—and at two others considered to be under mixed pollution influences; a sixth sample was obtained from an open sea area to act as background control. The organic matter (EOM) associated with the mineral substrata was extracted; after cleanup, analyte determination was carried out by HRGC-LRMS(SIM) using isotopically labeled compounds as internal standards. Cumulative levels of the selected PAHs were found to be in the range of 0.065 to 0.46 μg/g of dry matrix at five sites; a much higher concentration (48 μg/g) was detected in the sample from the urban environment. The remarkable PAH level increase at this site was mostly accounted for by the concurrent, apparent increase of EOM contamination as PAH concentration was seen to reach 32 μg/mg of EOM from <1 μg/mg at the five remaining sites. Mutagenicity assays withSalmonella typhimuriumstrains TA98 and TA100 of marine sediment organic extracts also highlighted a distinct activity in the sample from the urban site. Further fractionation and analysis of this extract pointed to PAHs as the main mutagenic component present in the sediment matrix, possibly accounting for up to approximately 70–80% of the entire mutagenic potential detected.     

Mutagenicity study of urine from smoking and non-smoking road tanker drivers

Summary Urine from 32 road tanker drivers handling petrol, diesel, paraffin and white spirit was tested in the Salmonella/microsome mutagenicity system using tester strains TA98 anbd TA100. Urine samples were collected before and after tanking and were concentrated 250-fold on XAD-2 columns before testing. Controls were 33 office employees from the same plant. No effect on urinary mutagenicity of occupational exposure to petroleum products was found. Significant differences in mutagenic effect were demonstrated between smokers and non-smokers. Methodological experiments demonstrated a dose/response effect of smoking on urinary mutagenicity. A modified test using a preincubation period and an increased concentration of bacteria was more sensitive than the standard Ames test to mutagens from tobacco smoking.     

Mutagenicity of fume particles from stainless steel welding.

Welding fume particles collected from different welding procedures were tested for mutagenicity in Escherichia coli, with the inhibition zone in pol A- as compared to pol A+, and in Salmonella typhimurium, TA 100 strain. While no mutagenicity was found with mild steel welding, a mutagenic effect was established with samples from stainless steel welding. This mutagenicity was particularly associated with manual metal arc (MMA) welding, and less so with metal inert-gas welding. A decrease in or an elimination of the effect occurred with a liver microsomal metabolizing system (S-9 mix). The MMA samples produced the strongest mutagenic effect. More-detailed investigations on these samples showed that the mutagenic agent(s) is water soluble. An increased mutagenicity, which also revealed the induction of frame shift mutations, was found with TA 98. The same welding fume sample was used for a mutagenicity test (resistance to 6-thioguanine) with V 79 hamster cells. Because of the high toxicity of these welding fume particles on the cells, only very low concentrations could be tested, but the increase of mutations, when compared to the negative control, was significant. It is suggested that hexavalent chromium may be involved in the mutagenic effect of the welding fumes.     

八氯二丙醚的致突变性和致畸性研究

为探讨八氯二丙醚的致突变性和致畸性，采用Ａｍｅｓ试验、小鼠骨髓嗜多染红细胞微核试验、传统致畸试验进行了检测。结果发现：Ａｍｅｓ试验中仅有两个浓度的回变菌落数为阴性对照的两倍以上，但无剂量反应关系；致畸试验在８０，３２０和１６００ｍｇ／ｋｇ的染毒剂量条件下，没有发现明显的致畸作用。但１６００ｍｇ／ｋｇ的剂量对孕鼠和胎鼠都有一定的毒性作用。低剂量组胎鼠的体重和身长及尾长均高于阴性对照组。经统计学检验差     

六硝基六氮杂异伍兹烷的致突变性和致畸性研究

目的对高能量密度化合物六硝基六氮杂异伍兹烷(CL-20)的致突变、致畸毒性进行研究,为进一步评价其对接触人员可能造成的健康影响及制订卫生标准提供依据。方法选用健康ICR小鼠72只、SD大鼠56只,将72只小鼠随机分为5个染毒组,2个阴性对照组(植物油)和2个阳性对照组(环磷酰胺,CP),每组8只;5个染毒组分别以不同剂量染毒,进行小鼠致突变试验(包括Ames试验、小鼠骨髓细胞染色体畸变分析、小鼠骨髓嗜多染红细胞微核试验);对56只大鼠进行致畸实验。结果(1)致突变实验结果表现为对小鼠骨髓细胞有致染色体损伤作用和形成非整倍体,主要的畸变类型为断片及缺失。2 000、4 000 mg/kg剂量组与阴性对照组相比,诱发小鼠的微核率明显增高,差异有统计学意义(P<0.05)。Ames试验中,8～5 000μg/皿剂量范围内未发现CL-20的诱变作用。(2)致畸实验结果表明,100 mg/kg剂量时,CL-20对孕鼠有一定的毒性作用,但未发现CL-20的胚胎毒性及致畸性。结论CL-20有致突变性,无胚胎毒性及致畸性。     

基于辣椒碱鉴别“地沟油”的有效性评估

目的评估基于辣椒碱鉴别"地沟油"的有效性。方法采集食用植物毛油14份,煎炸废弃油脂24份,餐厨废弃油脂34份,市售食用非花生植物油32份,市售食用花生植物油32份,正常食用油加香精16份和自制"地沟油"精炼油11份,检测样品中天然辣椒碱、二氢辣椒碱、合成辣椒碱含量,对上述样品的辣椒碱检测结果以样品类别进行统计学检验,评估基于辣椒碱鉴别"地沟油"的有效性。结果辣椒碱指标检测灵敏度高,判定餐厨废弃油脂及精炼"地沟油"类样品有效性较高,准确率分别达100%及90.1%,但在食用花生植物油中有辣椒碱本底存在。结论辣椒碱在烹饪过程中作为辣椒调料添加引入的成分在油脂中能保留下来,在精炼过程中不能完全被去除,在充分排除本底干扰的情况下,结合其他指标可有效鉴别"地沟油"与食用植物油。     

2种燃料燃烧颗粒物致突变性及其联合作用

目的比较液化石油气（LPG）燃烧颗粒物和蜂窝煤燃烧颗粒物的致突变性以及二者的联合作用。方法采用Ames法,应用鼠伤寒沙门菌突变型菌株TA 98及其衍生菌株YG 1021和YG 1024进行致突变试验研究,并根据致突变试验结果评价其联合作用。结果2种颗粒物对YG菌株的致突变作用均高于对TA 98的作用;LPG燃烧颗粒物比蜂窝煤燃烧颗粒物的致突变作用更强,前者约相当于后者的8倍;二者的联合作用呈相加类型。结论煤和LPG燃烧颗粒物均具有很强的直接和间接致突变作用,主要致突变作用来源于硝基和胺基多环芳烃,2种颗粒物同时存在可加大致癌风险。