Neurobehavioral effects and hormones profile among spray painters

Neurotoxicity of organic solvents with emphasis on the role of iron

BACKGROUND

Exposure to organic solvents (OS) adversely affects different body systems, the central and peripheral nervous systems being the most susceptible ones.

OBJECTIVES

This study investigated the role of iron in association with some neurotransmitters for diagnosis of neurotoxicity of OS.

METHODS

The study included 90 workers, 50 occupationally exposed to OS and 40 representing control group. Blood samples were collected from the included subjects for determination of serum iron, total iron binding capacity (TIBC), serotonin and gamma-aminobutyric acid (GABA).

RESULTS

Revealed reduction in serotonin level and serum iron. However, the elevation in GABA and TIBC was observed. The duration of exposure was significantly correlated with iron and serotonin while it was positively correlated with GABA and TIBC.

CONCLUSIONS

Elevated GABA and TIBC with decreased serotonin and serum iron can be used as early diagnostic measures to detect the neurotoxic effects of OS.

Determinants of Airborne Solvent Exposure in the Collision Repair Industry

Objectives

To assess the determinants of airborne solvent exposures in contemporary vehicle collision repair workplaces.

Methods

Personal, full-shift airborne solvent exposures (n = 97) were assessed in 85 vehicle collision repair workers from 18 workshops. Peak exposures were assessed using a small number of video exposure monitoring measurements.

Results

Solvent exposures were highest in spray painters (geometric mean = 2.7 ppm) followed by panel beaters (0.5 ppm), but were well below workplace exposure standards. The lowest exposure levels were observed for mixing room extraction located away from the mixing bench [exposure ratio (ER) = 0.51, 95% confidence interval (CI) = 0.30-0.87]. Time spent mixing paint was associated with higher exposures (ER for every 10-min increase = 1.14, 95% CI = 1.05-1.24), as was time spent cleaning equipment with solvents (ER = 1.11, 95% CI = 0.88-1.39), spraying primer (ER = 1.10, 95% CI = 0.96-1.27), and spraying clear coat paint (ER = 1.07, 95% CI = 1.00-1.15). Overall, the combined non-spray painting tasks (mixing paint, degreasing, and cleaning equipment) were more strongly associated with exposure (ER = 1.10, 95% CI = 1.03-1.18) than the combined spray painting tasks (ER = 1.03, 95% CI = 1.00-1.05). Peak exposures ranged from 10 to 1100 ppm with the strongest and most frequent peaks occurring during paint mixing, decanting of solvents, cleaning of equipment, and painting in a cross-draft spray booth.

Conclusions

Airborne solvent exposures in the collision repair industry were associated with job title, the design and location of exhaust ventilation and emission sources, and time spent on specific tasks, with the highest average and peak exposures shown for non-spray painting tasks. These findings provide a contemporary basis for intervention programmes to reduce airborne solvent exposures in this industry.

Thyroid Function Disruptors: from nature to chemicals

The modern concept of thyroid disruptors includes man-made chemicals and bioactive compounds from food that interfere with any aspect of the hypothalamus-pituitary-thyroid axis, thyroid hormone biosynthesis and secretion, blood and transmembrane transport, metabolism and local action of thyroid hormones. This review highlights relevant disruptors that effect populations through their diet: directly from food itself (fish oil and polyunsaturated fatty acids, pepper, coffee, cinnamon and resveratrol/grapes), through vegetable cultivation (pesticides) and from containers for food storage and cooking (bisphenol A, phthalates and polybrominated diphenyl ethers). Due to the vital role of thyroid hormones during every stage of life, we review effects from the gestational period through to adulthood, including evidence from in vitro studies, rodent models, human trials and epidemiological studies.

Renal and hepatotoxic alterations in adult mice on inhalation of specific mixture of organic solvents

This study was aimed at investigating alterations in renal and hepatic toxicity induced by exposing to a combination of three solvents, namely, benzene, toluene and xylene in adult mice. The mice were divided into three groups (control, low-dose-treated (450 ppm) and high-dose (675 ppm) groups) using randomization methods. The treated groups were exposed to vapours of a mixture of benzene, toluene and xylene at doses of 450 and 675 ppm, for 6 h day(-1) for a short-term of 7-day exposure period. The study revealed that the solvent exposure resulted in an increase in the weight of liver and kidney as compared to the control. Biochemical analyses indicated a significant decline in the activities of superoxide dismutase and catalase in both the treated groups, with concomitant increase in lipid peroxidation. Liver aminotransferases (alanine aminotransferase and aspartate aminotransferase) were elevated with significant alterations in the levels of protein, creatinine and cholesterol in these tissues upon solvent exposure. Correlated with these changes, serum thyroid hormones T3 and T4 were also significantly altered. This study, therefore, demonstrates that inhalation of vapours from the solvent mixture resulted in significant dose-dependent biochemical and functional changes in the vital tissues (liver and kidney) studied. The study has specific relevance since humans are increasingly being exposed to such solvents due to increased industrial use in such combinations.