Biochemical Biomarkers

HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

The metabolic effects of omega-6 polyunsaturated fatty acids (PUFAs) remain contentious, and little evidence is available regarding their potential role in primary prevention of type 2 diabetes. We aimed to assess the associations of linoleic acid and arachidonic acid biomarkers with incident type 2 diabetes. We did a pooled analysis of new, harmonised, individual-level analyses for the biomarkers linoleic acid and its metabolite arachidonic acid and incident type 2 diabetes. We analysed data from 20 prospective cohort studies from ten countries (Iceland, the Netherlands, the USA, Taiwan, the UK, Germany, Finland, Australia, Sweden, and France), with biomarkers sampled between 1970 and 2010. Participants included in the analyses were aged 18 years or older and had data available for linoleic acid and arachidonic acid biomarkers at baseline. We excluded participants with type 2 diabetes at baseline. The main outcome was the association between omega-6 PUFA biomarkers and incident typ...

The metabolic effects of omega-6 polyunsaturated fatty acids (PUFAs) remain contentious, and little evidence is available regarding their potential role in primary prevention of type 2 diabetes. We aimed to assess the associations of linoleic acid and arachidonic acid biomarkers with incident type 2 diabetes. We did a pooled analysis of new, harmonised, individual-level analyses for the biomarkers linoleic acid and its metabolite arachidonic acid and incident type 2 diabetes. We analysed data from 20 prospective cohort studies from ten countries (Iceland, the Netherlands, the USA, Taiwan, the UK, Germany, Finland, Australia, Sweden, and France), with biomarkers sampled between 1970 and 2010. Participants included in the analyses were aged 18 years or older and had data available for linoleic acid and arachidonic acid biomarkers at baseline. We excluded participants with type 2 diabetes at baseline. The main outcome was the association between omega-6 PUFA biomarkers and incident typ...

HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés. Distributed under a Creative Commons Attribution-NonCommercial| 4.0 International License

Biomarkers are recognised sensitive early-warning tools of biological effects in aquatic organisms. In this scope, the main aim of this study was to investigate the potential usefulness of a battery of biomarkers, evaluated in different benthic macroinvertebrate taxa, to discriminate aquatic ecosystems with different levels of ecological status and to provide further clues supporting environmental management. The study took place during the autumn of 2013 and the spring and summer of 2014, and the study cases were two Mediterranean rivers (Âncora and Ferreira rivers), differing in their ecological status. The biomarkers determined are widely employed and comprise a large set of biochemical responses: the activity of enzymes (cholinesterases, glutathione S-transferases, catalase and lactate dehydrogenase) and the levels of lipid peroxidation. They were assessed seasonally and in different macroinvertebrate taxa. Thirteen water physico-chemical parameters were also seasonally determined, and the concentration of seven organophosphorus pesticides and the percentage of 32 trace metals in sediments were determined in the spring. This is particularly useful for water management. Based on this, authorities can take actions to prevent further damage in the ecological status. Multivariate analyses showed distinct patterns of biological response for the Calopteryx spp., Chironomidae and Baetis spp. taxa. Calopteryx spp. and Chironomidae, in particular, showed distinct response patterns for the two rivers, which were fairly stable across seasons. This study sets the foundations for future cost-effective biomonitoring campaigns in Mediterranean rivers, allowing to establish historical data important to understand ecosystem evolution, as well as baseline levels of diagnostic biomarkers in informative macroinvertebrate taxa.

Biomarkers are recognised sensitive early-warning tools of biological effects in aquatic organisms. In this scope, the main aim of this study was to investigate the potential usefulness of a battery of biomarkers, evaluated in different benthic macroinvertebrate taxa, to discriminate aquatic ecosystems with different levels of ecological status and to provide further clues supporting environmental management. The study took place during the autumn of 2013 and the spring and summer of 2014, and the study cases were two Mediterranean rivers (Âncora and Ferreira rivers), differing in their ecological status. The biomarkers determined are widely employed and comprise a large set of biochemical responses: the activity of enzymes (cholinesterases, glutathione S-transferases, catalase and lactate dehydrogenase) and the levels of lipid peroxidation. They were assessed seasonally and in different macroinvertebrate taxa. Thirteen water physico-chemical parameters were also seasonally determined, and the concentration of seven organophosphorus pesticides and the percentage of 32 trace metals in sediments were determined in the spring. This is particularly useful for water management. Based on this, authorities can take actions to prevent further damage in the ecological status. Multivariate analyses showed distinct patterns of biological response for the Calopteryx spp., Chironomidae and Baetis spp. taxa. Calopteryx spp. and Chironomidae, in particular, showed distinct response patterns for the two rivers, which were fairly stable across seasons. This study sets the foundations for future cost-effective biomonitoring campaigns in Mediterranean rivers, allowing to establish historical data important to understand ecosystem evolution, as well as baseline levels of diagnostic biomarkers in informative macroinvertebrate taxa.

The purpose of this study was to identify the long-term effect of chemical exposure on the liver. Laboratory tests included alanine aminotransferase (ALT) dosage and oxidative stress tests, such as thiobarbituric acid reactive substances in plasma and superoxide dismutase (SOD) and glutathione S-transferase analysis in erythrocytes. The cross-sectional study comprised 70 workers, 30 of them exposed to organic solvents and 40 not exposed. All those exposed presented at least 5 years of exposure to solvents. Hepatitis B and C, known hepatic disease, comorbidities, use of alcohol, illicit drugs or hepatotoxic medications, smoking, body mass index >30, female sex and age (<18 or >65) were excluded from the sample. Results indicated that elevated ALT was more frequent in the exposed group compared to controls: 33% vs. 10.5%, with a statistical significance (p < 0.05). Thiobarbituric acid reactive substances were significantly elevated (p < 0.01) in the exposed group in comparison to controls. Antioxidant enzymes were more elevated in the exposed group compared to controls: SOD 7.29 (4.30-8.91) USOD/mg of protein vs. 3.48 (2.98-5.28) USOD/mg of protein and GST 2.57 mmol/min/mg of protein (1.80-4.78) vs. 1.81 mmol/min/mg of protein (1.45-2.30) mM/min/mg of protein. The results suggest an association between exposure to organic solvents and hepatotoxicity.

Several studies have reported toxicological implications of inhalational exposure to petrol fumes in animal models; however, there is little or no documentation on the probable effect of exposure in human subjects. This study investigated the relationship between exposure to petrol fumes and lipid peroxidation and antioxidant levels among petrol station attendants in Ibadan, SouthWest Nigeria A total of 150 subjects consisting of 100 petrol attendants and 50 control subjects were recruited. Ten mL of blood was collected from ante-cubital vein of subjects for analysis. Results reveal that exposure to petrol fumes is associated with oxidative stress. Significant (p<0.001) elevation of malondialdehyde was associated with marked decreases in superoxide dismutase (p<0.01), catalase (p<0.001) and glutathione (p<0.05) when compared with the control. Chain breaking antioxidant vitamins results include significant (p<0.05) decreases in vitamin E and no significant difference in vitamin C (p>0.05) when compared with control. Also there was a significant decrease in total protein (p<0.05) but no significant difference in albumin (p>0.05) in petrol attendants compared with the control. Our findings imply that exposure to petroleum fumes is a risk factor and is associated with oxidative stress which raises the need for public awareness about the health hazards in order to enable petrol attendants to take necessary precautionary measures.

The aim of this study was to appraise the response of a multi-marker approach in fish species, Gobius niger and Zosterisessor ophiocephalus, in a polluted lagoon (Bizerte lagoon: MB and ML sites) and in a reference site (Ghar-El-Melh lagoon entrance) by the analysis of physiological indexes, liver histopathology and some biochemical biomarkers. The results showed liver hypertrophy in fish collected from Bizerte lagoon as well as many nonspecific lesions, unlike the reference site. All Bizerte lagoon sites had the same prevalence of histopathological lesions, but the mean intensity (MI) of parasites seemed to be more sensible as an indicator of pollution levels. Indeed, parasite MI was more important in MB site that has a higher pollution level. Also, biochemical biomarkers showed an induction in Bizerte lagoon sites with some differences within sites and species. The impact of the continuous release of pollution on the biomarker's response is discussed.

The metabolic effects of omega-6 polyunsaturated fatty acids (PUFAs) remain contentious, and little evidence is available regarding their potential role in primary prevention of type 2 diabetes. We aimed to assess the associations of linoleic acid and arachidonic acid biomarkers with incident type 2 diabetes. We did a pooled analysis of new, harmonised, individual-level analyses for the biomarkers linoleic acid and its metabolite arachidonic acid and incident type 2 diabetes. We analysed data from 20 prospective cohort studies from ten countries (Iceland, the Netherlands, the USA, Taiwan, the UK, Germany, Finland, Australia, Sweden, and France), with biomarkers sampled between 1970 and 2010. Participants included in the analyses were aged 18 years or older and had data available for linoleic acid and arachidonic acid biomarkers at baseline. We excluded participants with type 2 diabetes at baseline. The main outcome was the association between omega-6 PUFA biomarkers and incident typ...

The metabolic effects of omega-6 polyunsaturated fatty acids (PUFAs) remain contentious, and little evidence is available regarding their potential role in primary prevention of type 2 diabetes. We aimed to assess the associations of linoleic acid and arachidonic acid biomarkers with incident type 2 diabetes. We did a pooled analysis of new, harmonised, individual-level analyses for the biomarkers linoleic acid and its metabolite arachidonic acid and incident type 2 diabetes. We analysed data from 20 prospective cohort studies from ten countries (Iceland, the Netherlands, the USA, Taiwan, the UK, Germany, Finland, Australia, Sweden, and France), with biomarkers sampled between 1970 and 2010. Participants included in the analyses were aged 18 years or older and had data available for linoleic acid and arachidonic acid biomarkers at baseline. We excluded participants with type 2 diabetes at baseline. The main outcome was the association between omega-6 PUFA biomarkers and incident typ...

We compared behavioural (burrowing speed), biochemical (acetylcholinesterase [AChE] inhibition, activities of digestive enzymes) and physiological (feeding and egestion rates, condition) responses in Nereis diversicolor originating from a multipolluted estuary (Loire estuary) and a relatively clean site (Bay of Bourgneuf) on 3 occasions during spring 2008. Significant inhibition of AChE and digestive enzymes (amylase and carboxymethylcellulase) activities were recorded in individuals from the Loire estuary compared to the reference site. At the individual level no significant intersite differences in burrowing speed were observed when ragworms were exposed to their sediment of origin. No link between AChE activity and burrowing behaviour was found in worms from either site. Cross-tests revealed that behavioural disturbances in locomotion were not due to neurological dysfunction but to avoidance of contaminated sediments. Feeding and egestion rates were depressed significantly in worms originating from the Loire estuary compared to the reference site. These behavioural impairments were accompanied by changes in digestive enzyme activities, which can explain the generally poorer condition of ragworms from the Loire estuary. Temporal changes in responses reported in the present study underline the importance of the fluctuation of environmental factors and thus the need for more than one sampling series to assess the health status of a given site. Disturbances at the different levels of biological organisation are likely explained by environmental contamination either chronic in the Loire estuary or the result of a small oil spill.

The Manila clam Venerupis philippinarum is a good biomonitor/bioindicator to marine metal pollution and is frequently used in aquatic toxicology. Two dominant pedigrees (white and zebra) of clam are distributed in the Bohai Sea; however, little attention has been paid to potential biological differences between these two pedigrees. In this study, we tested the sensitivity of both pedigrees to marine metal (cadmium and zinc) pollution biomonitoring and marine environmental toxicology. Results demonstrate signifi cant biological differences in gills of white and zebra clams based on metabolic profi les and antioxidant enzyme activities. In addition, we found that hypotaurine, malonate and homarine were relatively high in white clam gills, while alanine, arginine, glutamate, succinate, 4-aminobutyrate, taurine and betaine were high in zebra clam gills. Zebra clam gills were also more sensitive to a mixture of Cd and Zn, as shown by antioxidant enzyme activities and metabolic profi les, but white clam gills could accumulate more Zn. Therefore, we suggest that the white pedigree can be used as a biomonitor to marine Zn pollution, whereas the zebra pedigree can be used for toxicology studies on Cd and Zn mixed pollution.

The influence of volatile organic solvents (nitrocellulose thinner, gasoline and xylene) on the activity quotient and liver biochemical indices of laboratory mice, Mus musculus over a period of 60 days were evaluated. The study entailed the use of a modified nose inhalation exposure method in which the exposure chambers were saturated with the test chemicals for 8 hours daily following which they were transferred to the vapour-free section of the chamber. The estimation of activity quotient by day 60 indicated that mice exposed to xylene were most restless followed by nitrocellulose thinner and gasoline (least restless) with activity quotient values of 0.69, 0.58 and 0.21 respectively. The results of the biochemical indices showed that there was a significant decrease (p<0.05) in the levels of antioxidant enzymes such as reduced gluthathione (GSH), superoxide dismutase (SOD) and catalase (CAT) in exposed mice from day 21 to 60 compared to control. Furthermore, the level of lipid peroxidation indicated by malondialdehyde (MDA) was found to be significantly higher (p<0.05) in exposed mice compared to control. The significance of these findings is that workers (laboratory technicians, painters and gasoline station attendants) who are occupationally exposed to these volatile organic solvents for elongated periods may be at risk of lung related disorders.

Background: Petrol, xylene, and thinner are volatile organic compounds (VOCs), a major class of pollutants that affect the chemistry of the atmosphere and animals including man. The principal mode of contamination is via inhalation. This study aims to elucidate the effects of these compounds on bio-chemical functions in the body of the mouse, Mus musculus Methods: One hundred and twenty adult albino Mus musculus species were randomly assigned to groups (A1, A2, B1, B2, C1, C2, and D1) based on their weights (8-13g for juveniles and 15 – 21g for adults) with specific treatments. The control treatment, A1, was housed in a plastic experimental house free from the test chemical vapor while groups A2 and B1; B2 and C1; C2 and D1 were exposed to pet-rol, thinner, and xylene respectively in wooden exposure chambers for six hours daily for sixty days. Levels of oxidative stress markers (GSH, SOD, CAT, and MDA) were determined using the spectrophotometry. Results: A significant decrease in t...

Gasoline or petrol is the generic term for petroleum fuel used for internal combustion of engines. Petroleum fumes are ubiquitous in our environment and the common sources of contact or exposure are petrochemical industries (refineries, oils field, and filling stations) and homes. Also the daily use of petroleum outside the industrial settings is likely to have effect on users. The present review compiles the epidemiological studies done in various parts of world on the harmful effects of petroleum products.The available studies suggest that petroleum products are more toxic to liver and kidney as compared to other organs, No conclusive studies are available to support the role of petroleum products in skin, respiratory ,reproductive and neuropsychiatric disorders.

Gasoline or petrol is the most common fuel used for vehicles. Petroleum vapours are present in high concentrations around petrol pumps and are harmful in nature. The present review compiles the studies done in various parts of world on the deleterious effects of petroleum products.The available studies suggest that petroleum products are nephrotoxic and hepatoxic. No conclusive studies are available to support the role of petroleum products in skin, respiratory,reproductive and neuropsychiatric disorders.

The effects of volatile organic solvents (nitrocellulose thinner, gasoline and xylene) inhalation on the haematological and histological indices of laboratory mice, Mus musculus over a period of 60 days were evaluated. The study entailed the use of a modified nose inhalation exposure method in which the exposure chambers were saturated with the test chemicals for 8 hours daily following which they were transferred to the vapour-free section of the chamber. Estimation of haematological parameters in the blood of exposed and control mice collected with haematocrit tubes through the eyes were carried out on days 21, 45 and 60 using electronic coulter counter (ADVIA-TM 60). Lung tissue sections were obtained from dissected mice randomly selected from the exposed and control groups on days 21, 45 and 60 and prepared for histological studies. The haematological effects in exposed mice include a marked increase in white blood cells (WBCs) and decrease in red blood cells (RBCs), packed cell...

The effects of volatile organic solvents (nitrocellulose thinner, gasoline and xylene) inhalation on the haematological and histological indices of laboratory mice, Mus musculus over a period of 60 days were evaluated. The study entailed the use of a modified nose inhalation exposure method in which the exposure chambers were saturated with the test chemicals for 8 hours daily following which they were transferred to the vapour- free section of the chamber. Estimation of haematological parameters in the blood of exposed and control mice collected with haematocrit tubes through the eyes were carried out on days 21, 45 and 60 using electronic coulter counter (ADVIA-TM 60). Lung tissue sections were obtained from dissected mice randomly selected from the exposed and control groups on days 21, 45 and 60 and prepared for histological studies. The haematological effects in exposed mice include a marked increase in white blood cells (WBCs) and decrease in red blood cells (RBCs), packed cel...

The effects of volatile organic solvents (nitrocellulose thinner, gasoline and xylene) inhalation on the haematological and histological indices of laboratory mice, Mus musculus over a period of 60 days were evaluated. The study entailed the use of a modified nose inhalation exposure method in which the exposure chambers were saturated with the test chemicals for 8 hours daily following which they were transferred to the vapour-free section of the chamber. Estimation of haematological parameters in the blood of exposed and control mice collected with haematocrit tubes through the eyes were carried out on days 21, 45 and 60 using electronic coulter counter (ADVIA-TM 60). Lung tissue sections were obtained from dissected mice randomly selected from the exposed and control groups on days 21, 45 and 60 and prepared for histological studies. The haematological effects in exposed mice include a marked increase in white blood cells (WBCs) and decrease in red blood cells (RBCs), packed cell volume (PCV) and platelets count (PLT) when compared to control mice. The histology of the lungs of the exposed mice revealed considerable inflammation of the lungs, mild oedema and haemorrhage in a number of bronchial tissues when compared to mice in the control group. The results revealed that exposure to vapours of these solvents may be a risk factor for haematotoxicity and histopathology in individuals such as painters, gasoline station attendants and laboratory technicians who are occupationally exposed to them. The need for sensitization and awareness programmes on the potential health effects posed by these compounds and their inclusion in monitoring programmes are consequently recommended.

The effects of volatile organic solvents (nitrocellulose thinner, gasoline and xylene) inhalation on the haematological and histological indices of laboratory mice, Mus musculus over a period of 60 days were evaluated. The study entailed the use of a modified nose inhalation exposure method in which the exposure chambers were saturated with the test chemicals for 8 hours daily following which they were transferred to the vapour-free section of the chamber. Estimation of haematological parameters in the blood of exposed and control mice collected with haematocrit tubes through the eyes were carried out on days 21, 45 and 60 using electronic coulter counter (ADVIA-TM 60). Lung tissue sections were obtained from dissected mice randomly selected from the exposed and control groups on days 21, 45 and 60 and prepared for histological studies. The haematological effects in exposed mice include a marked increase in white blood cells (WBCs) and decrease in red blood cells (RBCs), packed cell...

Occupational toxicity as a result of exposures to hazardous chemicals is common in industries using solvents based materials as well as in indoor environments, including painters, , where they exposed to volatile organic compounds. The present study was designed to evaluate health problems and metals-related toxicities among painters in Sulaimani city. A cross sectional study was performed on 35 male painters and twenty non-exposed healthy subjects were included as a control group. Venous blood samples were obtained and analyzed for hematology markers and the serum were utilized for estimation of liver enzyme activity, total bilirubin, serum levels of lead, chromium, and reduced glutathione. The results showed non-significant change in total serum bilirubin between the groups, while liver enzyme activities were significantly increased in the workers. The hematological markers showed a significant increase in Hb level in painters and no significant changes in hematocrit and platelet count between both groups. The data also showed a significant increase in total WBC in painters, and significant increase in the level of lead and non-significant increase in the level of chromium in painters. The level of GSH decreased significantly in painters. In conclusion, evaluation of occupational toxicity in painters in Sulaimani city did not reveal potential health hazards.

Key words: Painters, Liver toxicity, Hematological toxicity, Heavy metals, Glutathione.

The influence of volatile organic solvents (nitrocellulose thinner, gasoline and xylene) on the activity quotient and liver biochemical indices of laboratory mice, Mus musculus over a period of 60 days were evaluated. The study entailed the use of a modified nose inhalation exposure method in which the exposure chambers were saturated with the test chemicals for 8 hours daily following which they were transferred to the vapour-free section of the chamber. The estimation of activity quotient by day 60 indicated that mice exposed to xylene were most restless followed by nitrocellulose thinner and gasoline (least restless) with activity quotient values of 0.69, 0.58 and 0.21 respectively. The results of the biochemical indices showed that there was a significant decrease (p<0.05) in the levels of antioxidant enzymes such as reduced gluthathione (GSH), superoxide dismutase (SOD) and catalase (CAT) in exposed mice from day 21 to 60 compared to control. Furthermore, the level of lipid peroxidation indicated by malondialdehyde (MDA) was found to be significantly higher (p<0.05) in exposed mice compared to control. The significance of these findings is that workers (laboratory technicians, painters and gasoline station attendants) who are occupationally exposed to these volatile organic solvents for elongated periods may be at risk of lung related disorders.

The influence of volatile organic solvents (nitrocellulose thinner, gasoline and xylene) on the activity quotient and liver biochemical indices of laboratory mice, Mus musculus over a period of 60 days were evaluated. The study entailed the use of a modified nose inhalation exposure method in which the exposure chambers were saturated with the test chemicals for 8 hours daily following which they were transferred to the vapour-free section of the chamber. The estimation of activity quotient by day 60 indicated that mice exposed to xylene were most restless followed by nitrocellulose thinner and gasoline (least restless) with activity quotient values of 0.69, 0.58 and 0.21 respectively. The results of the biochemical indices showed that there was a significant decrease (p<0.05) in the levels of antioxidant enzymes such as reduced gluthathione (GSH), superoxide dismutase (SOD) and catalase (CAT) in exposed mice from day 21 to 60 compared to control. Furthermore, the level of lipid peroxidation indicated by malondialdehyde (MDA) was found to be significantly higher (p<0.05) in exposed mice compared to control. The significance of these findings is that workers (laboratory technicians, painters and gasoline station attendants) who are occupationally exposed to these volatile organic solvents for elongated periods may be at risk of lung related disorders.

The effects of volatile organic solvents (nitrocellulose thinner, gasoline and xylene) inhalation on the haematological and histological indices of laboratory mice, Mus musculus over a period of 60 days were evaluated. The study entailed the use of a modified nose inhalation exposure method in which the exposure chambers were saturated with the test chemicals for 8 hours daily following which they were transferred to the vapour- free section of the chamber. Estimation of haematological parameters in the blood of exposed and control mice collected with haematocrit tubes through the eyes were carried out on days 21, 45 and 60 using electronic coulter counter (ADVIA-TM 60). Lung tissue sections were obtained from dissected mice randomly selected from the exposed and control groups on days 21, 45 and 60 and prepared for histological studies. The haematological effects in exposed mice include a marked increase in white blood cells (WBCs) and decrease in red blood cells (RBCs), packed cell volume (PCV) and platelets count (PLT) when compared to control mice. The histology of the lungs of the exposed mice revealed considerable inflammation of the lungs, mild oedema and haemorrhage in a number of bronchial tissues when compared to mice in the control group. The results revealed that exposure to vapours of these solvents may be a risk factor for haematotoxicity and histopathology in individuals such as painters, gasoline station attendants and laboratory technicians who are occupationally exposed to them. The need for sensitization and awareness programmes on the potential health effects posed by these compounds and their inclusion in monitoring programmes are consequently recommended.

The influence of volatile organic solvents (nitrocellulose thinner, gasoline and xylene) on the activity quotient and liver biochemical indices of laboratory mice, Mus musculus over a period of 60 days were evaluated. The study entailed the use of a modified nose inhalation exposure method in which the exposure chambers were saturated with the test chemicals for 8 hours daily following which they were transferred to the vapour- free section of the chamber. The estimation of activity quotient by day 60 indicated that mice exposed to xylene were most restless followed by nitrocellulose thinner and gasoline (least restless) with activity quotient values of 0.69, 0.58 and 0.21 respectively. The results of the biochemical indices showed that there was a significant decrease (p<0.05) in the levels of antioxidant enzymes such as reduced gluthathione (GSH), superoxide dismutase (SOD) and catalase (CAT) in exposed mice from day 21 to 60 compared to control. Furthermore, the level of lipid peroxidation indicated by malondialdehyde (MDA) was found to be significantly higher (p<0.05) in exposed mice compared to control. The significance of these findings is that workers (laboratory technicians, painters and gasoline station attendants) who are occupationally exposed to these volatile organic solvents for elongated periods may be at risk of lung related disorders.