Testing for mutagens in filter samples from the work atmosphere of an aluminum plant

Filter extracts of airborne particles from a S?derberg potroom and an anode paste plant were tested for mutagenicity by the Salmonella reversion assay. The extracts were mutagenic to strains TA100 and TA98, mainly after metabolic activation, but positive results were obtained also without S9 mix in strain TA98. These findings indicate that the particulate phase of air from the potroom and the anode paste plant of aluminum plants contain mostly indirect mutagens of both the base-pair substitution and frameshift type, and--to a less degree--frameshift mutagens. The relationship between concentration and mutagenicity was more positive for the potroom extract than for the anode paste plant extract.     

Mutagenicity of rice-straw and -husk ashes by Ames test]

In the rice-producing district of Japan, environmental pollution by smoke from burnt rice straws has become a matter of concern. The mutagenicity of fly- and bottom-ashes of rice-straw and -husk was assayed by the Ames test, TA100 +/- S9 and TA98 +/- S9, and the relationship of combustion temperature to mutagenicity was investigated. Fly ash showed weak mutagenicity at 300 degrees C, with no remarkable change in mutagenic activity between 300 degrees C and 500 degrees C. Above 500 degrees C the mutagenic activity increased with a rise of temperature. The increasing rate of mutagenicity was much higher in the test system with S9 mix than that without S9. Moreover, the mutagenicity with TA100 was stronger than with TA98. With respect to bottom ash, weak mutagenic activity was observed at 300 degrees C, but at 400 degrees C decreased and at 500 degrees C or above could not be observed. Fly ash derived from burning 1 g of rice straw at 600 degrees C showed about 14 times and 2.5 times higher mutagenicity than main stream smoke condensates from the burning of 1 g of cigarette in TA100 + S9 and TA98 + S9 test systems respectively.     

Mutagenicity of drinking water obtained by different treatment procedures from two northern Italian lakes

Raw water and drinking water samples collected from four treatment plants supplied by two north Italian lakes were studied for their mutagenic activity. The samples were concentrated on XAD‐2 columns and the adsorbates were tested at increasing doses with the Ames test, using Salmonella typhimurium TA98 and TA100 strains, with and without metabolic activation. Raw water from both lakes was found to contain direct‐acting mutagens detectable with TA98 strain. The analysis of water from the four treatment systems showed that new mutagens detectable with strain TA100 (?S9) were produced when pre chlorination or post chlorination with NaCIO was performed, as previously found by other authors. When chlorine dioxide and/or ozone were used, TA98 mutagenicity was reduced and no new mutagens were produced. The results showed the applicability of the Ames test to evaluate drinking water treatment processes and to produce additional data useful in the detection of potential health hazards associated with drinking water production.     

Mutagenicity of organic pollutants adsorbed on airborne particles in the center of Wrocław

With Ames assay there was examined mutagenicity of airborne particles that was sampled in summer and winter in centre of Wroc?aw; there were also examined fractions of aliphatic hydrocarbons, aromatic hydrocarbons and polar compounds obtained from suspended matter extracts suspended with column chromatography. The strain of Salmonella typhimurium TA 98 was used with metabolic activation with S9 mix fraction. The samples collected in winter was more mutagenically active than the one sampled in summer. Mutagenicity of suspended matter sampled in summer was determined by compounds that were of more polar character than polycyclic aromatic hydrocarbons soluble in hexane. There was observed a decrease in mutagenic activity of samples in summer due to metabolic activation. There were few polycyclic aromatic hydrocarbons on the dust sampled in summer and they did not display mutagenic activity. Mutagenicity of air particles sampled in winter was determined by polycyclic aromatic hydrocarbons soluble in hexane and polar compounds. There was observed an increase in their mutagenic activity due to metabolic activation. This demonstrates that among them there are present promutagens, which, in mammals, undergo enzymatic transformation to compounds of direct mutagenic activity. Fractions of aliphatic hydrocarbons in the examined range of concentrations did not display mutagenic activity neither in summer nor in winter, both with and without metabolic activity.     

Monitoring exposure of hospital personnel handling cytostatic drugs and contaminated materials

A study was undertaken to evaluate the urine mutagenicity of 63 individuals working in four hospital departments. The exposed group included 38 subjects who were exposed to various cytostatic drugs and/or contaminated material from treated patients. The control group included 25 individuals of the hospital personnel. Urine mutagenicity was monitored by the Ames test using tester strains TA 98 + S9 Mix and TA 102 — S9 Mix. Urine samples were collected before and after the working periods. A total of 29/116 (25%) urine samples were mutagenic for either strain. Among the mutagenic samples, 24/29 were mutagenic for tester strain TA 98 exclusively. No significant correlation could be found between occupational exposure to cytostatic drugs and urine mutagenicity evaluated by the strain TA 98 + S9 Mix. Smoking was the main environmental factor that modulated urine mutagenicity with TA 98. Three subjects in the exposed group had mutagenic urine samples at the end of the working period with strain TA 102 — S9 Mix. This mutagenicity was related to occupational exposure to cisplatin. In the control group, one individual had mutagenic samples before and after the working period. Assessing occupational exposure to cytostatic drugs with strain TA 102 requires additional studies to determine environmental mutagens which can be detected by this strain.     

Correlations between mutagenicity of airborne particles and concentrations of air pollutants]

With highly efficient aspirometry method there were sampled airborne particles in different parts of Wroc?aw in winter and summer. Organic compounds adsorbed on the particles were extracted for 8 hours in Soxhlet apparatus. Concentration of PAHs and benzo(a)pyrene was determined with GC-MS. Mutagenicity of particles was examined with Ames test. Concentrations of airborne particles ranged from 17-144 mg/m3, and organic compounds adsorbed on the particles--1.1-28.6 mg/m3. Concentrations of PAHs from EPA list ranged from 8.3-1211.6 ng/m3, benzo(a)pyrene's ones--from 4.5-709 ng/m3. Airborne particles sampled in many different locations of Wroc?aw in winter and summer displayed mutagenic activity. Air volumes polluted with the particles resulting in mutagenic effect in Ames test in TA 98 strain without activation with fraction S9 ranged from 0.25-42.5 m3. They displayed correlation with concentration of airborne particles (correlation index -0.35), organic compounds adsorbed on the particles (correlation index -0.58), PAHs from EPA list (correlation index -0.52) and benzo(a)pyrene (correlation index -0.52). Physiochemical indexes of air pollution only approximately indicate health hazards caused by mutagenes and cancergenes adsorbed on airborne particles. Therefore monitoring of air pollution should be supplemented with testing their mutagenicity with Ames test.     

自来水厂出厂水有机物遗传毒性及其影响因素

目的 研究某市不同自来水厂出厂水中有机物的遗传毒性作用,探讨水源、消毒剂种类、有无预加氯和活性炭二次过滤对出厂水有机物遗传毒性的影响.方法 于2008年5-6月,采集某市6家不同水源、不同水处理工艺的自来水厂(A、B、C、D、E、F)出厂水水样.通过鼠伤寒沙门菌致突变(Ames)试验(设0、0.25、0.50、1.00L/皿4个浓度)检测水样中有机物的致突变性,采用比活性的参数方法比较不同来源水样的致突变性强弱.结果 6个自来水厂出厂水中有机物的Ames试验结果均为阳性.各自来水厂出厂水中有机物的致突变比活性比较结果如下,TA98(-S9):E>D>C>A>F>B;TA98(+S9):E>C>F>D(A、B为阴性);TA100(-S9):E>F>C>A(D、B为阴性);TA100(+S9):仅E为阳性.结论 某市自来水厂出厂水中的有机物具有明显的致突变作用,且以移码突变为主;使用江河水、取消预加氯消毒、以二氧化氯消毒剂取代液氯消毒剂以及使用活性炭二次过滤技术可减少致突变有机物的生成.

Abstract：

Objective To study the genotoxicity of the organic extracts from the product water of water plants and the affection of water source.disinfechant type,prechlorination and bioactive carbon filtration on the genotoxicity.Methods Ames testWaS used to test the mutagenicity of water samples from six water plants from May to June.2008.Resnits All of the product watersamples of six water Works (A,B,C,D,E,F)showed positive results in Ames test.The mutagenicity showed as follows:TA98(-S9):E>D>C>A>F>B;TA98(+S9):E>C>F>D(A,B were negative);TA100(-S9):E>F>C>A(D、B were negative);As for TA100(+S9),only E Wag positive.Conclusion The mutagenicity of product water of six water works is relatively high,the type of mutagenicityiS mainly code.shifting.Taking river water as the water source.using chlorine dioxide and active carbon filtration and no usingpretreatment of chlorination may reduce the mutagenic organics.     

The results of microbial mutation test for forty-three industrial chemicals

The mutagenicity of 43 industrial chemicals in Salmonella typhimurium (TA98, TA100, TA1535, TA1537, and TA1538) and Escherichia coli (WP2uvrA) was examined. The output of these chemicals in Japan is more than a million kilograms per year. The mutation test was carried out under the condition of absence and presence of rat microsomal activation. Two chemicals, hexamethylenetetramine and 4,4'-methylenediphenyldiisocyanate, showed mutagenic activity in S. typhimurium TA98 and TA100 by metabolic activation. Hexamethylenetetramine also showed mutagenic activity in TA98 without microsomal activation. No mutagenic activity was observed in the 41 chemicals including 4 volatile and gaseous compounds.     

Handling of cytostatic drugs and urine mutagenesis

Summary As part of a French national epidemiologic study on human reproduction among hospital personnel, we investigated urine mutagenicity of nurses and personnel from oncology units exposed to cytostatic drugs. During a first series of experiments, urine mutagenicity of 47 subjects working in six oncology units was investigated in the Marseille regional's hospital. A control group of 37 individuals working in one cardiology clinic was also included. Urinary mutagens were extracted on XAD-2 resin and tested by two bacterial mutagenicity tests: the Ames test with tester strains Salmonella typhimurium TA 97, TA 98, TA 100 and TA 102 with or without metabolic activation (S9 MIX) and the SOS Chromotest with tester strain Escherichia coli PQ 37-S9 MIX. Bactericidal activity towards the tester strains was found in 40% of the urine samples (36/90). During a second series of experiments, urine mutagenicity of 17 office clerks was also investigated. Toxicity was found in six of the 21 urine samples. No significant difference of toxicity distribution and no relationship between toxicity and cigarette smoking were found. Qualitative analysis of the data showed no significant difference among the exposed groups and the control group (Chi 2 = 0.529, df = 2) with tester strain TA 98 + S9 MIX. Cigarette smoking was found to be the main factor of increased urinary mutagenicity (Chi 2 = 0.529, df = 1). Quantitative analysis of the data showed that mutagenic potencies varied from 0.332 ±0.539 revertants/mg creatinine to 7.226 ± 6.743 revertants/mg creatinine with TA 98 + S9 MIX. A relationship between the number of cigarettes smoked and mutagenic potency was found (Spearman rank coefficient r _s = 0.412, P < 0.05). One urine sample was found to be mutagenic with tester strain TA 102 and PQ 37.     

Mutagenicity of aliphatic and aromatic nitro compounds. Industrial materials and related compounds

Mutagenicity of 102 aliphatic and aromatic nitro compounds, industrial materials and related chemicals were tested by pre-incubation method using Salmonella typhimurium TA100 and TA98 strains with and without S9 mix. Escherichia coli WP2uvrA/pKM101 was also used in the mutagenicity assay of aliphatic nitro compounds. Four chemicals out of 8 aliphatic nitro compounds tested were mutagenic to TA100, TA98 and/or WP2 strains. Sixty-one out of 94 nitrobenzene derivatives were mutagenic to TA100 and/or TA98 strains. Thirty-seven chemicals among the 65 mutagens showed higher mutagenic activity than 1,000 rev./mg. The following 15 chemicals showed higher activity than 10,000 rev./mg: tetranitromethane, chloropicrin, 1,3,5-trinitrobenzene, 2,4-dinitrochlorobenzene, 2,3-dinitrophenol, 2,6-dinitroaniline, 3,5-dinitroaniline, 2-bromo-4,6-dinitroaniline, 2,4-dinitrofluorobenzene, p-nitrobenzylchloride, 3,5-dinitrobenzylchloride, p-nitrophenylhydrazine, 2,4-dinitrophenylhydrazine, 2,4-dinitrophenylthiocyanate and nitramine. Nitrobenzene was not mutagenic, but mono-substituted nitrobenzenes having-CH2Cl, -COCl, -NO2, -NH-NH2, -COOH, -OCH3, -NH2, -Br, -OH, -NH-NH2HCl, -OP(OC2H5)2S or -CHO group showed mutagenic. Introduction of-Cl, -CH3, -C2H5 or -SO3H group to nitrobenzene did not contribute to mutagenicity. Mutagenicity of dinitrobenzene was enhanced by the introduction of -F, -SCN, -NH2, -Cl, -CH2Cl, -NO2, -NH-NH2 or -COCl group, and suppressed by the introduction of -COOH or -CH3 group. Twenty-three out of 45 chemicals for which "exposure limits" are established from the stand point of industrial hygiene in many countries in the world, were mutagenic to TA100, TA98 and/or WP2 strains. Furthermore, 42 out of 57 chemicals for which "exposure limits" are not established were also mutagenic. The following three carcinogens, that is, 2-nitropropane, 2,4-dinitrotoluene and 2,6-dinitrotoluene, were all mutagenic, but their mutagenic activity was weak. Many chemicals were found to have a stronger mutagenic activity and a chemical structure similar to carcinogenic dinitrotoluenes. This fact suggests the necessity of conducting carcinogenic assay of these chemicals.     

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.     

冬季重污染天气大气PM_(2.5)致突变性的初步研究

目的利用鼠伤寒沙门菌回复突变试验(Ames试验)测定冬季重污染天气下PM_(2.5)的致突变性。方法利用大流量采样器收集冬季优良天气及重污染天气PM_(2.5),PM_(2.5)全颗粒物剂量为100、250、500和1 000μg/皿,选用TA98菌株,采用平板掺入法进行Ames试验。结果优良天气下收集的PM_(2.5)在500、1 000μg/皿-S9剂量组及1 000μg/皿+S9剂量组致突变率(MR)2且有剂量-效应关系;严重污染天气下收集的PM_(2.5)在250、500和1 000μg/皿±S9剂量组MR2且有剂量-效应关系。结论 PM_(2.5)全颗粒物对TA98具有一定的致突变效应。     

Correlation between mutagenicity of airborne particles and air pollution parameters in eleven Italian towns

Organic extracts from airborne particles collected in 11 Italian towns between February and April, 1988, were tested for mutagenicity on TA98 and TA100 (± S9), and their nitroreductase (NR) deficient Salmonella strains, by the use of the Ames plate incorporation assay. Mutagenic responses were fitted by an equation which takes into account toxic effects on tester organisms. Generally parallel responses were obtained with the two Salmonella strains, but the TA98 gave, mostly, higher increases of revertants over the control level. No dramatic decreases in mutagenicity were observed with the NR derivative strains, except in a few cases with TA98NR and, more frequently, with TA100NR strains. During air sampling, temperature, atmospheric pressure, light, wind strength and direction, SO₂, CO, NO₂, O₃ and non‐methanic hydrocarbons (NMHC) concentrations were continuously monitored. Meteorological variables seem not to be significantly correlated with mutagenicity variations, while the highest correlation (r = 0.91) was observed between induced reversion in TA98 (+ S9) and NMHC concentration in air. Therefore, in spite of the wide range of different types of towns included in the study, air NMHC concentration can be considered a good predictor for the mutagenicity of the total organic material extracted from particles of urban air.     

Air pollution survey in Kitakyushu district

Airborne particulate samples were collected on a glass fiber filter or quartz filter using Hi-volume air sampler from November, 1980 through February, 1983 at a west part of Yahata district, Japan. The concentrations of airborne particulates, polynuclear aromatic hydrocarbons (PAH), heavy metals and dustfall were determined, and mutagenic activities of tarry materials obtained from suspended particulates were also measured. The following results were obtained. (1) The airborne particulate contents were 22.1 - 188 mg/1000 m3 (mean : 74.6 mg/1000 m3), and the values were high in spring and low in summer. (2) PAH contents in airborne particulates were in the following order: benzo(ghi)perylene greater than benzo(a)pyrene greater than benz(a)anthracene greater than chrysene greater than benzo(k)fluoranthene greater than pyrene greater than perylene. PAH contents were higher in winter that in summer. The benzo(a)pyrene contents were 1.97 micrograms/1000 m3 in 1981 and 1.92 micrograms/1000 m3 in 1982. (3) Heavy metals content was about 2.1 - 3.6 higher in winter in comparison with that in summer time. (4) Mutagenic activity showed 90 - 11900 revertants/1000 m3 for TA 98 strain with S-9 mix and 50 - 7190 revertants/1000 m3 for TA 98 strain without S-9 mix. Mutagenic activities for TA 98 with S-9 mix were higher than those for TA 98 without S-9 mix. (5) As a result of the analysis of airborne particulate samples, a significant correlation was observed between mutagenic activities and the concentrations of PAH and heavy metals. These results indicated that the mutagenic survey may be useful as an index for air pollution study.     

Toxicity reduction evaluation at a municipal wastewater treatment plant using mutagenicity as an endpoint

Previous work revealed substantial levels of mutagenicity in effluents from certain municipal wastewater treatment plants. One of these treatment plants was selected for further study to track the effluent mutagenicity to its sources, to chemically characterize the mutagenicity, and to assess the treatability of the mutagens. Mutagenicity testing using the Salmonella/microsome assay was performed on methylene chloride extracts of influent and effluent samples from the municipal wastewater treatment plant, as well as on four selected industrial effluents entering the plant. The mutagenicity of the influent samples was detected only in the presence of a microsomal metabolic activation system and was highest in Salmonella strain TA98. About two-thirds of the mutagenicity passed through the treatment plant, suggesting that the mutagenic compounds were refractory to conventional biological treatment. No significant mutagenic activity was detected in three of the industrial waste streams, all paper products plant discharges. However, a high level of mutagenicity (1.2 million TA98 revertants/liter) was detected in the effluent from a coke oven plant. This source could account for all of the mutagenicity entering the wastewater treatment plant. After fractionation of the coke oven effluent by sequential extraction at neutral, acidic and basic pH with methylene chloride, 93% of the TA98 (+S9) mutagenicity was found in the neutral fraction. A C₁₈ column fractionation scheme using a methanol/water elution gradient revealed that 92% of the mutagenicity eluted with the 75% and the 80% methanol in water fractions. The C₁₈ fractionation also provided good separation of mutagenicity from toxicity to fathead minnows. This study has demonstrated the potential of toxicity reduction evaluation (TRE) methodology for tracing effluent toxicity to its source, using genotoxicity as an endpoint.Disclaimer. This article has been reviewed by the U.S. Environmental Protection Agency and approved for publication. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.     

Application of the Salmonella mutagenicity assay and determination of polycyclic aromatic hydrocarbons in workplaces exposed to petroleum pitch and petroleum coke

Summary Workplaces of an Italian carbon electrode factory, exposed to petroleum pitch and petroleum coke, were studied using a coupled chemical and biological approach to evaluate occupational mutagenic/carcinogenic hazards. Analytical procedures for the determination of polycyclic aromatic hydrocarbons (PAH) and Salmonella/microsome mutagenicity tests (with TA98 and TA 100 strains) were performed on both industrial ingredients (pitch and coke) and airborne particulate matter of the working environment, after fractionating by sequential Soxhlet extractions with four organic solvents of increasing polarity (benzene, chloroform, methanol and acetone). The results showed: (a) the presence of extraordinarily high PAH (carcinogenic and noncarcinogenic) contents in the benzene extracts of petroleum pitch (3.6 wt% of total PAH) and of airborne particulate samples (up to 0.35 wt% of total PAH), in correlation with very high indirect (after metabolic activation) mutagenic responses of benzene extracts with strain TA98; (b) very high indirect mutagenic responses in the other extracts of the airborne particulate samples (especially with strain TA98); (c) the production during the processing at high temperatures of directly acting mutagens (without metabolic activation) which were absent in the starting materials and their release in the air of workplaces. The comparison of chemical analytical and mutagenicity data has proved to be an interesting approach for better defining the relative health hazards due to occupational exposure to potentially mutagenic/carcinogenic petroleum products.     

Validity of mutagenic activity as an indicator of river water pollution

Objectives To investigate if mutagenicity could be expressed by known water pollution indicators, we determined the mutagenic activity of blue rayon extracts from sampled river water with the Ames test utilizing new strains of bacteria, and compared the results with those of known indicators of water pollution. Methods Water samples were collected by the blue rayon adsorption method at sixteen sites in six rivers in the North Kyushu district. The Assay of mutagenicity was carried out using the Ames test. The test strains wereSalmonella typhimurium TA100, YG1024, YG1041 and YG1042. B(a)P, Trp-P-1 and Trp-P-2 were quantified by HPLC. Determinations of SS, BOD, COD, T-N, T-P, DOC, and A₂₆₀/DOC were performed. Results The extracts from five sampling sites showed higher mutagenicity toward strain YG1024 with or without S9mix, and the extracts from two of these five sites showed higher mutagenicity toward strain YG1041 with and without S9mix. However, the water pollution indicators did not show specific trends that were consistent with the mutagenic activity. Conclusions Since the mutagenic activity of river water could not be predicted using known water pollution indicators, we recommend that biological examinations such as mutagenicity tests be added to the indicators that are currently in use.     

Carcinogenicity of extract of airborne particles using newborn mice and comparative study of carcinogenic and mutagenic effect of the extract

An organic extract of airborne particles collected in Tokyo and its fractions (neutral, acidic, and basic) were investigated in Ames Salmonella assays for mutagenicity and in newborn mice for carcinogenicity. Mutagenicity to TA100 and TA98 strains was detected in the whole extract, the neutral, the acidic and the basic fractions with and without metabolic activation. In the carcinogenicity test, the incidence of lung tumor was as follows: whole extract, 4/25; neutral fraction, 7/25; acidic fraction, 0/20; basic fraction, 1/11; vehicle, 2/39; and uninjected, 3/47. The neutral fraction of the extract of the airborne particles showed highly potent mutagenicity and a high incidence of lung tumors in mice.     

The mutagenic hazards of environmental PM2.5 in Turin

Owing to the large number of natural and anthropogenic sources, particulate matter (PM) may present several physical and chemical patterns in different areas. The finer PM2.5 fraction, which is now widely but not routinely measured in Europe, is considered to be the alveolar fraction of the ambient particles. Annual and winter mean concentrations of PM2.5 substantially vary in Europe, with higher concentrations in the South. The aims of this work were to (a) measure the PM2.5 levels in Turin over a long period, (b) evaluate mutagenic activities of organic extracts containing this collected complex mixture using the Ames test and (c) determine the level of polycyclic aromatic hydrocarbons (PAHs) in order to identify important mutagens in ambient air. Sampling was carried out from November 2001 to December 2004. The monthly mean of PM2.5 was 48.76+/-24.12 microg/m3. From the beginning to the end of the sample period there was a decrease in gravimetric levels, with annual means of 54.10+/-29.77 microg/m3 in 2002; 42.48+/-15.73 microg/m3 in 2003 and 45.89+/-24.92 microg/m3 in 2004. Samples were tested for mutagenicity using Salmonella typhimurium strains TA98 and TA100, with and without S9 mix metabolic activation. A positive genotoxic response was observed for TA98, with and without metabolic activation. The measured PAHs monthly mean level was 8.24+/-6.30 ng/m3, with values ranging from 0.20 to 21.38 ng/m3 Seasonal variation of gravimetric, mutagenic and PAH values was significant. The Salmonella assay results statistically correlated to PM2.5 and PAHs levels, but sometimes the mutagenic potencies were rather different despite an equal concentration of pollutant. The results confirm the usefulness of this biological approach to detect genotoxic properties of sampled PM2.5 and they show the variability of the mutagenic properties of the airborne mixture over time.     

Mutagenicity and antimutagenicity testing of six chemicals associated with the pungent properties of specific spices as revealed by the Ames Salmonella/microsomal assay

Three compounds, capsaicin, thymol and borneol, were initially screened for mutagenic activity using Salmonella typhimurium strains TA97, TA98 and TA100, with and without S9 metabolic activation, and 20 min standard preincubation time. Three other compounds, allyl isothiocyanate, eugenol and cinnamaldehyde, were screened for mutagenic activity as above, but with a prolonged, nonstandard preincubation time of up to 120 minutes. All six test compounds used in the assays are associated with the pungent properties of some specific spices in which the test compounds can be found to exist naturally. The first objective of this study was to observe if mutagenic activity can be correlated to the pungent properties of these six test compounds. However, due to toxicity and the observation that only capsaicin was mutagenic, using strain TA100 in the presence of S9 metabolic activation, it was not possible to deduce any relationship between mutagenicity and the test chemials' pungent properties. Naturally occurring capsaicin, found in the spice Capsicum annum, was detected and quantified using thin layer and gas chromatographic techniques.The final objective was to detect the presence of antimutagenic factor(s) in C. annum that would suppress the mutagenicity of capsaicin. When the mutagenic capsaicin and 2-aminoanthracene were assayed in the presence of C. annum acetone extract, using strain TA100 with S9 metabolic activation, the mutagenic response of both the mutagens were reduced by approximately 50%. Assaying capsaicin and 2-aminoanthracene in the presence of chlorophyll, the mutagenic response of the two mutagens was reduced by less than 40%. From this observation it was inferred that chlorophyll can successfully suppress the mutagenicity activities of capsaicin and 2-aminoanthracene, together with other antimutagenic factors that were present in the acetone extract of C. annum.