Short-term exposure to ozone and levels of exhaled nitric oxide.

BACKGROUND: Adverse effects of air pollution include respiratory inflammation. A few epidemiologic studies have shown elevations in the fraction of exhaled nitric oxide, a marker of airway inflammation, after exposure to traffic-related pollutants. METHODS: We examined whether short-term exposures to ozone (O3), oxides of nitrogen (NOx), or particulate matter <10 µm (PM10) were associated with proximal and distal airway inflammation. The study included 5841 randomly selected Swedish adults from 25 to 75 years of age. Fraction of exhaled nitrogen was measured at two flow rates: 50 ml/s representing the proximal airways and 270 ml/s representing the distal airways. Air pollution data were obtained from an urban monitoring site. We applied linear regression to estimate short-term associations of O3, NOx, and PM10 with fractions of exhaled NO at 50 and 270 ml/s. RESULTS: An interquartile range increase in 120-hour average O3 levels was associated with a 5.1% (95% confidence interval = 1.7% to 8.5%) higher level of fraction of exhaled NO at 270 ml/s and 3.6% (-0.4% to 3.4%) higher level of the fraction of exhaled NO at 50 ml/s. For NOx, a small effect was seen for the 24-hour average on the fraction of exhaled NO at 270 ml/s, while for PM10 no clear effects were seen. There was a tendency for a weaker effect of ozone and a stronger effect of NOx in subjects with asthma. CONCLUSIONS: Exposure to O3 was associated with a marker of distal airway inflammation, while the association was less obvious for inflammation of the proximal airways.

Occupational skin exposure and hand eczema among dental technicians-need for improved prevention.

OBJECTIVES: The aims of this study were to estimate occupational skin exposure, the use of skin protection, and the incidence of hand eczema among dental technicians. METHODS: In a retrospective cohort study, dental technicians (N=2139) and randomly selected population controls (N=2288) received a postal questionnaire on occupational skin exposure, protective glove use, and hand eczema, including the year of onset. The response rate was 57% for the dental technicians and 58% for the controls. RESULTS: Altogether 80% of the dental technicians reported skin exposure to uncured (meth)acrylates (MA), and 87% had skin contact with grinding dust from MA. Thirty-nine percent used protective gloves when handling uncured MA. Twenty-two percent of the currently employed technicians reported participation in obligatory training concerning the handling of thermosetting plastics, and 58% did not know how long normally used gloves protected the skin against uncured MA. Altogether 48% of the dental technicians and 30% of the controls reported more than 10 hand washings a day (P<0.001). For the dental technicians, the incidence of hand eczema was 8.5 cases/1000 person-years during MA-exposed time. For the controls, the incidence was 3.3. The incidence rate ratio for the men was 3.6 (95% CI 2.3-5.6), and for the women it was 2.4 (95% CI 1.7-3.3). CONCLUSIONS: The work of dental technicians involves frequent and unprotected exposure to MA and frequent hand washings. Dental technicians have twice the risk of hand eczema than the general population. Efforts to improve skin protection and increase participation in obligatory training about handling thermosetting plastics are important.