Jia et al. (2002) studied the dermatologic effects of gasoline exposure among 52 female sewing machine workers in a cross-sectional study in China. The women were exposed daily (7 hours a day) to 500 mL of gasoline in cleaning and applying transfers or decals to the machines. The workplace was ventilated, and the concentration of gasoline in the air was below the maximum allowed, 300 mg/m3. The women were matched by age with female workers of similar SES from a spinning mill (n=52). Of the 52 exposed and nonexposed workers, 30 were sampled and interviewed about their occupational history, frequency of hand-washing during the day, and use of skin-care products. Skin samples were collected from the back of their hands to determine stratum corneum lipid concentrations (ceramide, fatty acid, and cholesterol) because these lipids were hypothesized to have been dissolved by the fuel exposure. The results showed that prevalences of hyperkeratosis, dryness, onychosis, and dermatitis were increased among the exposed compared with the non-exposed. The prevalence ratios were 3.33 (p<0.05) for hyperkeratosis; 3.00 (p<0.001) for dryness; 11.25 (p<0.001) for onychosis; and 5.00 (p<0.001) for dermatitis. The authors reported that most workers developed dermatitis within 1 month of starting to use gasoline and that all workers had been exposed for at least a year. Stratum corneum lipid concentrations were significantly lower in the exposed group. The authors did not report whether the skin and nail changes continued after exposure ceased.
Another cross-sectional study (Jee et al. 1985) examined the prevalence of dermatitis and exposure to kerosene among ball-bearing factory workers in Taiwan. Kerosene is used as a degreasing agent in the factory. Seventy-nine female workers who were identified as being exposed were compared with 263 workers employed at a zipper-manufacturing company. The groups had similar age distributions, educational backgrounds, and income levels. Safety personnel at the ball-bearing plant classified the 79 workers into two groups on the basis of exposure. Those classified as heavily exposed to kerosene (n=34) had direct contact for about 5 hours/day and wore gloves without inner gloves for about 3 hours/day. Those considered lightly exposed (n=45) did not wear gloves during the day.
Two dermatologists examined the hands and forearms of the heavily and lightly exposed and the nonexposed. They found that 84% of those exposed to kerosene (either heavily or lightly) had dermatitis compared with only 1% of the nonexposed. Among those heavily exposed, 91% had dermatitis; among those lightly exposed 78%. Dermatitis was classified as erythema (65% in both groups), eczema (15% in both groups), or defatting (4% in both groups), but the data were not stratified by type of dermatitis. Patch testing via the standard trays of the National Taiwan University Hospital and the American Academy of Dermatology was performed on five of 12 exposed workers who had severe eczema, and four of the five tested negative. The role and effects of other exposures in the factory (such as to antirust oil) cannot be ruled out. No information was provided on whether the dermatologists were blinded to the exposure status of each worker.
Venn et al. (2001) studied nearly 10,000 adults and children living in Jimma, a city in Ethiopia, to explore the risk of allergy in relation to increased use of cleaner fuels (kerosene, gas, and electricity) in the home. The city is in the midst of a transformation from biomass fuel, which is burned in open fires in poorly-ventilated homes, to cleaner fuels for heating and cooking. The study was prompted by clinicians’ observation of increasing rates of asthma and allergies. The city has no major industry, has light traffic levels, and is otherwise not polluted. The study collected symptom and lifestyle questionnaire data and results of allergen skin testing on a subset of 2,372 adults and children. It compared subjects who used a mix of cleaner fuels and biomass to a group that used only biomass fuel. After adjusting for age, sex, and SES, the