Genotoxicity of aerosol extracts: Some methodological aspects and the contribution of urban and industrial locations

The genotoxicity of aerosol extracts was investigated with the Ames test and an SCE test in vitro. In addition to experiments to evaluate current techniques, a so-called gradient study was carried out in an industrialized part of The Netherlands to obtain insight into the contribution of urban and industrial locations to the genotoxicity of aerosol extracts. The influence of variations in the sampling was investigated. The results indicate that moderate variations in the volume of air sampled per unit of time and of the duration of the sampling period do not have a great influence on the effect measured.Experiments with filters impregnated with ¹⁴C-labelled benzo[a]pyrene showed that this compound is converted during sampling into directly active mutagens; no evaporation occurred. The results of experiments to evaluate the extraction procedure indicated that an 8-h Soxhlet extraction with methanol is better than, or as good as, Soxhlet extraction with other solvents.The gradient study showed that the aerosol downwind from industrial/urban areas exerted a reproducibly stronger effect in the Ames test and the SCE test when compared with aerosol from sea air.     

Sister-chromatid exchange and chromosome aberrations for 4 aliphatic epoxides in mice

Sister-chromatid exchange (SCE) and chromosome aberrations (CA) in bone marrow cells were analyzed after in vivo exposure in mice to 4 aliphatic epoxides, namely 1-naphthyl glycidyl ether (NGE), 1-naphthyl propylene oxide (NPO), 4-nitrophenyl glycidyl ether (NPGE) and trichloropropylene oxide (TCPO). These compounds were selected as being among the most mutagenic aliphatic epoxides in our previous structure-mutagenicity studies with the Ames test. There were significant dose-related increases in SCE and CA results for all 4 epoxides. The order of genotoxicity as established through SCE was NGE greater than NPO greater than NPGE approximately equal to TCPO greater than solvent control. It is of interest that Ames Salmonella results are consistent with in vivo genotoxicity for these compounds. However, only the plate test version of the Ames procedure is consistent with this order of in vivo genotoxicity and neither preincubation Ames testing results nor chemical alkylation rates would have predicted this order.     

Genotoxicity testing of extracts of a Swedish moist oral snuff

The present study was designed to investigate the potential genotoxicity of aqueous and methylene chloride extracts of Swedish moist oral snuff. The test systems were selected to provide optimal data for the prediction of carcinogenicity in rodents and included assays for the induction of mutation in bacteria, sister-chromatid exchanges (SCE) in human lymphocytes, of chromosome aberrations and gene mutations in V79 Chinese hamster cells and of micronuclei in mouse bone marrow cells. In addition, the methylene chloride extract was tested for the induction of sex-linked recessive lethal mutations in Drosophila melanogaster. The aqueous extract of 'Snus' induced SCE in human lymphocytes and chromosome aberrations in V79 cells, the latter effect being observed both with and without metabolic activation. No induction of point mutations was detected with the Ames test or in V79 cells and the micronucleus test in mice was negative. It was demonstrated that the induction of chromosome aberrations without metabolic activation may be due to a high salt concentration, indicating that the clastogenic agent(s) in this extract required metabolic activation. The methylene chloride extract showed genotoxicity in the Ames test, the SCE test and the chromosome aberration test, whereas no induction of gene mutations in V79 cells was observed. Once again, the results suggested that metabolism is required for genotoxicity. The methylene chloride extract did not cause induction of micronuclei in mice or of sex-linked recessive lethal mutations in Drosophila melanogaster. These combined data on genotoxicity were analyzed using various models for the prediction of carcinogenicity. In a sequential testing model, the probabilities that the aqueous and methylene chloride extracts of 'Snus' are carcinogenic due to a genotoxic mechanism were both predicted to be low. Using carcinogenicity prediction by battery selection (CPBS), the probabilities of the methylene chloride and aqueous extracts being correctly identified as non-carcinogens are 71 and 77%, respectively. Up to date, the CPBS approach has been validated primarily for individual compounds, so some caution should at present be exercised in interpreting the results using this method. Based on these results, the carcinogenic potential of Swedish 'Snus' should be considered to be low, a conclusion in agreement with the low incidence of oral cancer in Sweden compared to other countries.     

In vitro genotoxic evaluation of conventional bleached and biobleached softwood pulp mill effluents

The effluents of pulp and paper mills contain about 300 different chemical compounds; many of them are mutagens and clastogens. Genotoxic studies have shown that chlorination stage liquors are significantly more genotoxic, in the Ames Salmonella assay, than the other process of lignin extraction, and that lyophilized effluents are genotoxic in cultured mammalian cells. Since these effluents from conventional bleaching stages are genotoxic, Chilean industries are interested in changing this process to a less toxic one, such as biobleaching using enzymes. In this study, we tested the in vitro genotoxicity of two types of effluents: an effluent obtained from a conventional radiata pine kraft-bleaching process (effluent D) and one derived from a biobleaching process with hemicellulase (effluent B). Both effluents were tested without any concentration or purification steps in the Ames Salmonella assay (TA100) and in the micronuclei (MN) and sister chromatid exchange (SCE) tests in CHO cells. The results showed that neither effluent induced base pair substitution mutations in the Ames Salmonella assay, and neither increased the micronucleus frequency in CHO cells. But, both increased the SCE frequencies in CHO cells, showing that this assay is more sensitive than the other ones, and that the two effluents contained chemical compounds in amounts enough to induce in vitro genotoxicity measured by the SCE induction.     

The Salmonella mutagenicity of industrial, surface and ground water samples of Aligarh region of India

The genotoxicity of three water bodies, viz. industrial waste water of Aligarh city, ground water pumped out from the industrial area of Aligarh, and river water of Yamuna, downstream of Agra, was carried out by means of Ames plate incorporation test and the Ames fluctuation test. All the test samples were significantly mutagenic in both the testing systems. The ground water and river water samples were subjected to XAD concentration prior to the mutagenicity/genotoxicity testing, while the industrial waste water was used directly. Whereas TA98, TA102 and TA104 strains have been found to be maximally sensitive in the Ames plate incorporation assay conducted for various water samples, TA98 and TA100 strains were the most responsive strains in the Ames fluctuation test. The apparent disparity in the sensitivity patterns of various Ames strains by plate incorporation and fluctuation assays could be attributed to a large extent to the different conventional ways of interpretation of the data in these systems.     

Genotoxic activity of organic contamination of the Songhua River in the north-eastern region of the People's Republic of China

The Songhua River is one of the biggest rivers in China and is the major freshwater source for industry and agriculture, as well as the source of the drinking water for millions of residents living along it. Heavy contamination of the Songhua River is due to domestic sewage and industrial wastewater. Thus, we set out to determine the carcinogenic potential of water samples taken from drinking water source of Harbin city in the Songhua River. Short-term genotoxic bioassays using Ames, SCE, and cell transformation assays were employed to examine the genotoxic activity of the ether extracts of water samples taken from the Songhua River. The results of the Ames test indicated that there were frame shift mutagens in the water samples, which were both direct and indirect. A dose–response relationship for the SCE assay was obtained, and the SCE cumulative frequency moved obviously to the right with increasing doses of water samples. Typical transformed foci were formed in NIH3T3 cells induced by ether extracts of water samples and the transformation frequency showed a dose–response relationship. The transformed cells showed the characteristics of malignant cells. All of the results indicated that the ether extracts of water samples taken from the Songhua River showed genotoxic activity.     

Genotoxicity and DNA adduct formation of incense smoke condensates: comparison with environmental tobacco smoke condensates

Indoor air pollution has now been recognized as a potentially important problem for public health, since people spend most of their day in closed environments. Incense burning is possibly associated with elevated risks of leukemia and brain tumor in children from the epidemiological studies. Thus, evaluation of the genotoxicity of smoke condensates from incense burning is needed. We examined the genotoxicity of incense smoke condensates (ISC) using the Ames test in S. typhimurium strains with different mutagenic specificity and level of metabolic enzyme, the SOS chromotest in E. coli PQ37, and sister chromatid exchange assay in Chinese hamster ovary cells (SCE/CHO). The genotoxicity of environmental tobacco smoke condensates (TSC) was also evaluated by the three assays to compare with the genotoxicity of ISC, ISC showed a positive response in TA98, but not in TA100. It suggested that ISC only contained frame shift mutagens. The mutagenicity of ISC in both strains of TA98NR with deficient nitroreductase and TA98/1,8-DNP₆ with deficient O-acetyl-transferase was markedly decreased compared to that in TA98 strain. However, the mutagenicity was enhanced in YG1024 with overexpression of O-acetyltransferase activity. Thus, nitroarenes seemed to be responsible in part for the mutagenicity of ISC. Interestingly, all of the four ISC and two TSC samples showed a dose-dependent genotoxic response in the SOS chromotest with E. coli PQ37 but a low SCE induction of those samples were observed in CHO cells. When the genotoxicity was analyzed based on the condensates per one gram of original samples, the genotoxicity of two TSC condensates in prokaryotic cells was higher than that of four ISC samples except for the genotoxicity of TSC-2 in TA98 strain. However, the genotoxicity of certain ISC in eukaryotic cells based on the SCE/CHO assay was higher than that of TSC. To compare the covalent binding of DNA reactive intermediates of ISC and TSC to S. typhimurium TA98, the DNA adducts were evaluated by the ³²P-postlabeling method with butanol extraction version. Similar diagonal radioactive zone (DRZ) was observed between ISC and CSC. However, DNA adduct levels induced by TSC were much greater than that of ISC.     

汉口、汉阳两地空气细颗粒物PM2.5遗传毒性研究

目的：探究汉口、汉阳两地空气细颗粒物PM2.5的遗传毒性。方法：采用Ames波动实验和双核细胞微核实验评价PM2.5在基因和染色体水平是否具有遗传毒性。结果：Ames波动实验结果表明,汉口和汉阳PM2.5对鼠伤寒沙门苗TA100无致突变作用;而在双核细咆徽核实验中,两地PM2.5随浓度上升徽核率逐渐上升,呈剂量反应关系,对染色体有损伤作用。2项实验结果都显示,汉口和汉阳两地的颗粒物在致遗传性上无明显差异。结论：汉口、汉阳两地PM2.5具有一定的潜在遗传毒性。     

Biological and environmental monitoring of occupational exposure to cyclophosphamide in industry and hospitals

The aims of the study were to clarify potential exposure situations to anticancer agents during industrial processing, drug manufacture and hospital administration, using cyclophosphamide (CP) as the model compound. CP is considered an animal and human carcinogen, and it is shown to be an indirect mutagen in various test systems using several genetic endpoints. Environmental monitoring was performed by collecting ambient air samples during the different processing and handling stages. Both stationary and personal sampling was used. CP was analyzed by liquid chromatography (HPLC) and mass spectrometry (MS). The process materials and intermediates were also analyzed for genotoxic activity using the Ames test and SCE induction in CHO cells as endpoints. Biological monitoring studies were performed on 147 persons representing 5 groups of workers, control subjects and patients. In the experimental part of the project, the intermediates in the CP manufacturing process, CP I (nor-nitrogen mustard) and CP II (phosphoroxydichloride mustard) were found directly active in the 2 genotoxicity tests. These findings led to improvements in work hygiene when handling CP I and CP II in the process. The CP measurements showed that the highest potential-exposure sites occurred during specific operations of the process, e.g., during emptying of the drying drum and during tablet mass preparation (the range of CP concentrations in air was 0.16-0.49 mg/m3). The correlation between indirect genotoxicity and chemical analyses of the ambient air samples was good, revealing the activity to be due to cyclophosphamide. However, the air samples were found mutagenic without metabolic activation also in the beginning of the process; this is obviously due to CP II particles in the ambient air, since no CP was detected chemically. The personal protection of workers in the plant collaborating in the study is efficient and the production unit is equipped with the best available techniques to protect both the personnel and the quality of the drug. Both the urine mutagenicity analyses using strain TA1535 of Salmonella typhimurium as indicator and the cytogenetic analyses of peripheral blood lymphocytes using sister-chromatid exchanges or structural chromosomal aberrations as endpoints were negative. However, a statistically nonsignificant trend in increased number of micronuclei was observed in binucleated lymphocytes of the worker groups as compared with controls. The studies on the hospital use of CP were performed in 3 oncological units and 1 pharmacy unit.(ABSTRACT TRUNCATED AT 400 WORDS)     

Genotoxicity of gliotoxin,a secondary metabolite of Aspergillus fumigatus,in a battery of short-term test systems

The genotoxic effects of gliotoxin, a known fungal secondary metabolite, were studied. Gliotoxin was purified from cultivation medium of Aspergillus fumigatus isolated from the indoor air of a moisture problem house. The genotoxicity of gliotoxin was assessed both in bacterial test systems including bacterial repair assay, Ames Salmonella assay and SOS-chromotest, and in mammalian cells using single cell gel (SCG) electrophoresis assay and sister-chromatid exchange (SCE) test. Gliotoxin was found to be genotoxic in the bacterial repair assay but, not in the Salmonella test or SOS-chromotest. A dose-related increase in DNA damage was observed in mouse RAW264.7 macrophages exposed to gliotoxin for 2h in plain medium in the SCG assay. In contrast to the positive response in the SCG assay, gliotoxin did not induce any clear, dose-related increase in SCEs in Chinese hamster ovary (CHO) cells.     

Comparative study of sister-chromatid exchanges and chromosomal aberrations induced by airborne particulates from an urban and a highly industrialized location in human lymphocyte cultures

Cytogenetic effects induced by extracts of airborne particulates in human lymphocyte cultures were studied with regard to local and seasonal variations. Samples of airborne particulates were collected from an urban and a highly industrialized area in March and October, respectively. All extracts of particulates induced a significant increase of sister-chromatid exchanges (SCE) in a dose-dependent manner. Referring to the induction of sister-chromatid exchanges, local and seasonal differences were observed. Samples from the industrialized area revealed the highest activities. In addition, SCE rates found for March samples were always higher than those for October for both locations. Furthermore, a remarkable, significant induction of chromosomal aberrations occurred with all samples from both locations and sampling periods. Aspects of health risk evaluation for exposed human populations are discussed with respect to the observed cytogenetic effects of airborne particulates in human lymphocyte cultures.     

Genotoxicity of gliotoxin, a secondary metabolite of Aspergillus fumigatus, in a battery of short-term test systems

The genotoxic effects of gliotoxin, a known fungal secondary metabolite, were studied. Gliotoxin was purified from cultivation medium of Aspergillus fumigatus isolated from the indoor air of a moisture problem house. The genotoxicity of gliotoxin was assessed both in bacterial test systems including bacterial repair assay, Ames Salmonella assay and SOS-chromotest, and in mammalian cells using single cell gel (SCG) electrophoresis assay and sister-chromatid exchange (SCE) test. Gliotoxin was found to be genotoxic in the bacterial repair assay but, not in the Salmonella test or SOS-chromotest. A dose-related increase in DNA damage was observed in mouse RAW264.7 macrophages exposed to gliotoxin for 2 h in plain medium in the SCG assay. In contrast to the positive response in the SCG assay, gliotoxin did not induce any clear, dose-related increase in SCEs in Chinese hamster ovary (CHO) cells.     

Multivariate optimisation of microwave-assisted extraction of capsaicin from Capsicum frutescens L. and quantitative analysis by 1H-NMR

A simple and rapid microwave-assisted extraction (MAE) procedure combined with 1H-NMR spectrometry was developed and optimised for the extraction and quantitative determination of capsaicin in Capsicum frutescens. The influence of experimental variables, including irradiation power, extraction temperature and dynamic extraction time before reaching the selected extraction temperature, on the performance of the extraction procedure was systematically studied using a Box-Behnken experimental design followed by a conventional central composite design approach. Statistical treatment of the results together with results from some additional experiments suggested optimum extraction conditions as 120 degrees C and 150 W, for 15 min with acetone as extractant. The optimised MAE method provides extracts that can be analysed quantitatively using 1H-NMR without any preliminary clean-up or derivatisation steps. In the 1H-NMR spectrum of the crude extracts the doublet signal in the delta range 4.349-4.360 ppm was well separated from other resonances in deuterated chloroform. The quantity of the compound was calculated from the relative ratio of the integral value of the target peak to that of a known amount of dimethylformamide as internal standard. In comparison with traditional Soxhlet extraction, the proposed method is less labour-intensive and provides a drastic reduction of extraction time and solvent consumption. In addition, MAE showed higher extraction yield and selectivity, with comparable reproducibility and recovery, relative to both conventional Soxhlet and sonication methods.     

薇甘菊提取物对螺旋粉虱的生物活性

【背景】薇甘菊和螺旋粉虱均为我国入侵物种,且二者之间无寄生关系。本研究旨在挖掘薇甘菊的利用价值,为其在螺旋粉虱生态防控中的使用提供依据。【方法】采用药膜法和田间喷雾法,研究了4种提取方法（冷浸法、索氏提取法、冷浸—索氏提取法、温浸法）获得的薇甘菊提取物对螺旋粉虱成虫的室内生物活性和田间防治效果。【结果】在所选择的4种提取方法中,索氏提取法和温浸法的提取率最高,分别为9.90%和9.35%;冷浸—索氏提取法和冷浸法的提取率相对较低,分别为7.73%和4.50%。室内生物测定表明,采用冷浸法、冷浸—索氏提取法、索氏提取法和温浸法所获得的薇甘菊提取物对螺旋粉虱成虫的LC50值分别为8.94、9.03、6.32和7.51 mg·mL-1,但由于95%置信区间存在重合,不同提取物活性之间的差异不显著。田间试验结果则表明,不同提取方法获得的薇甘菊提取物对螺旋粉虱成虫都具有良好的防治效果,100倍液处理7 d后,对螺旋粉虱的校正防效均在75%以上。但是,索氏提取法和温浸法提取物防治效果显著优于冷浸—索氏提取法和冷浸法。【结论与意义】薇甘菊提取物对螺旋粉虱具有生物活性。     

Assessment of genotoxicity of herbal medicinal products: Application of the “bracketing and matrixing” concept using the example of Valerianae radix (valerian root)

An assessment of genotoxicity is a precondition for marketing authorization respectively registration of herbal medicinal products (HMPs), as well as for inclusion into the ‘Community list of herbal substances, preparations and combinations thereof for use in traditional herbal medicinal products’ established by the European Commission in accordance with Directive 2001/83/EC as amended, and based on proposals from the Committee on Herbal Medicinal Products (HMPC).In the ‘Guideline on the assessment of genotoxicity of herbal substances/preparations’ (EMEA/HMPC/107079/2007) HMPC has described a stepwise approach for genotoxicity testing, according to which the Ames test is a sufficient base for the assessment of genotoxicity in case of an unequivocally negative result. For reducing efforts for testing of individual herbal substances/preparations, HMPC has also developed the ‘guideline on selection of test materials for genotoxicity testing for traditional herbal medicinal products/herbal medicinal products’ (EMEA/HMPC/67644/2009) with the aim to allow testing of a standard range of test materials which could be considered representative of the commonly used preparations from a specific herbal drug according to a ‘bracketing/matrixing’ approach.The purpose of this paper is to provide data on the practical application of this bracketing and matrixing concept using the example of Valerianae radix, with the intention of facilitating its inclusion in the “Community list”. Five extraction solvents, representing the extremes of the polarity range and including also mid-range extraction solvents, were used, covering the entire spectrum of phytochemical constituents of Valerianae radix, thereby including polar and non-polar constituents. Extracts were tested in the Ames test according to all relevant guidelines. Results were unequivocally negative for all extracts. A review of the literature showed that this result is in accordance with the available data, thus demonstrating the lack of a genotoxic potential.In conclusion the two guidelines on genotoxicity provide a practically applicable concept. Valerianae radix has no genotoxic potential, supporting its use in HMPs and its inclusion in the Community list.     

Genotoxic and mutagenic activity of environmental air samples from different rural, urban and industrial sites in Flanders, Belgium

The present study reports mutagenic and genotoxic activities associated with ambient air collected at 15 sites characteristic for urban, industrial or rural conditions in Flanders. Airborne particulates (PM10) and semi-volatile compounds were collected on quartz filters (QF) and polyurethane foam (PUF) cartridges using a high-volume sampling device. The mutagenic and genotoxic potency of the organic extracts – Soxhlet extraction with acetone – was determined by use of the Salmonella mutagenicity standard plate-incorporation assay and the Vitotox^® assay, respectively. Concentrations of 16 polycyclic aromatic hydrocarbons (PAHs) in the extracts were determined by reversed-phase high-performance liquid chromatography (HPLC).Ambient air samples contained significant PAH levels and mutagenic activities at all 15 sites: direct mutagenicity of up to 47 revertants per cubic meter was found in the QF extracts and more limited activity of up to 11 rev m⁻³ in the PUF extracts. Metabolic activation of PUF extracts resulted in an important increase in mutagenic activity, up to 30 rev m⁻³, but no such increase was observed for QF extracts. The highest values were observed outside large cities at industrial sites and at a rural site contaminated by pollution from a chemical plant at a distance of 4 km. Also at the background location near the North Sea a significant mutagenic activity was measured in the QF extracts (+S9: 9 rev m⁻³; −S9: 7 rev m⁻³). Apparently, there is in Flanders a significant background exposure level to airborne mutagenicity, even in areas with limited or no nearby pollution sources. Based on the concentrations of 10 mutagenic PAHs and supposing additivity of their specific mutagenicities, only a few percent (mean 3%) of the observed indirect mutagenic activity could be explained. This implies that most mutagenic activity originated from other substances that were not identified or measured in our chemical analysis. This underscores the importance of bio-monitoring measurements.     

Influence of extraction parameters on the mutagenicity of soil samples

The aim of this study was to investigate the influence of four extraction parameters (type of solvent, temperature, duration of extraction, and soil mass/solvent volume ratio) on the mutagenicity of soil extracts. Four urban soil samples were submitted to the micro-method adaptation of the Ames test on Salmonella typhimurium according to the following sequence: identification of the most sensitive strain (TA98 or TA100), the best solvent(s), the optimum extraction temperature and extraction time, and finally the optimal soil/solvent ratio. Extraction was thus performed using eight different solvents (distilled water, dichloromethane, acetonitrile, acetone, cyclohexane, methanol, hexane, or ethanol), two temperatures (room temperature or 37 degrees C), two durations (4 or 24 h), and two soil mass/solvent volume ratios (1:2 or 1:10). The results show that strain TA98 was more sensitive than strain TA100, and the observed mutagenicity was expressed as number of TA98 revertants per mg of soil equivalent. No mutagenicity was induced by the distilled water extracts, whereas most of the organic solvent extracts induced a significant mutagenic response. A dichloromethane/acetone mixture appeared to be the best compromise for extraction of mutagens from the urban soils tested. Moreover, the present study showed that a higher mutagenic activity was generally obtained with a temperature of 37 degrees C (compared to room temperature), with an extraction time of 24 h (compared to 4 h), and with a soil mass/solvent volume ratio of 1:10 (compared to 1:2).     

The genotoxicity of enantiomeric aliphatic epoxides

The (R)- and (S)-optical isomers of 9 epoxides, benzyloxymethyloxirane, epichlorohydrin, glycidol, glycidyl 3-nitrobenzenesulfonate, glycidyl 4-nitrobenzoate, glycidyl tosylate, styrene oxide, glycidyl 1-naphthyl ether and glycidyl 4-nitrophenyl ether, have been compared for their in vivo and in vitro genotoxicity. The in vitro short-term test employed was the Ames mutagenicity assay with Salmonella strain TA100. The in vivo tests were chromosomal aberrations (CA) as well as sister-chromatid exchange (SCE) in bone-marrow cells of mice following intraperitoneal administration of these epoxides. Differences in mutagenicity between isomers were established with TA100 for all the compounds. While 13 of the isomers were genotoxic compared to a negative control by CA measurements, only in the case of glycidyl 4-nitrobenzoate could a significant difference be found between isomers by this test. However, with SCE evaluations, differences were detected between the (R)- and (S)-isomers for all the pairs of compounds with the exception of those for benzyloxymethyloxirane and glycidyl 4-nitrophenyl ether. At least in part, differences in the patterns of genotoxicity among compounds can be related to their differences in reaction pathways.     

Indoor sources of mutagenic aerosol particulate matter: smoking, cooking and incense burning

The emission of aerosol particles and their mutagenic activity as well as the emission of some gaseous pollutants has been studied experimentally in order to compare the emission from some indoor pyrolysis processes. Cigarette (tobacco and herbal) smoking, incense and mosquito-coil burning and frying of experimental lean minced pork emitted particulate matter. Their extracts were mutagenic in the Ames Salmonella test with TA98 and activation as well as, with a higher response, in a microsuspension test with the same strain and activation condition. The response of the particles from the smoking and burning processes varied from 3000 to 50,000 revertants per gram of smoked or burnt material in the conventional Salmonella test and from 50,000 to 350,000 revertants per gram in the microsuspension assay. The frying of lean minced pork gave an airborne emission of about 53 and 560 revertants per gram of fried pork, respectively, in the 2 assays. The frying of some common food items following cookbook recipes also emitted mutagenic aerosol particles but the emitted activity was less than that in the pork experiment. Carbon monoxide, isoprene and benzene were present in the emissions from the smoking and burning processes but were not detectable in the frying fumes. The results suggest that incense and mosquito-coil burning can cause indoor air pollution akin to that from cigarette smoking. Indoor air pollution from cooking requires further study.     

美洲大蠊粪便粗提物的聚集活性

用不同溶剂不同方法提取美洲大蠊Periplaneta americana(L.)粪便,测定美洲大蠊各虫态的诱集活性。结果表明,采用直接浸泡提取方法,丙酮、乙醇、正己烷和二氯甲烷4种粗提物对美洲大蠊各虫态都具有明显的诱集作用,其中乙醇和丙酮粗提物的引诱效果最好,正己烷次之,二氯甲烷最弱。4种溶剂粗提物对美洲大蠊雄成虫和高龄若虫聚集活性最强,对低龄若虫聚集活性最弱。用乙醇溶剂对粪便粗提,3种提取方法均对美洲大蠊有很强的诱集效果,其中索氏抽提诱集效果最弱,直接浸泡和超声波提取效果好,且差异不显著,但直接浸泡提取效果更好。