We investigated whether the physical exercise of an olympic distance triathlon affected the salivary IgA excretion of triathletes, as a biomarker for mucosal immune defence. 42 triathletes participated in the study. It was found that the salivary flow rate was decreased significantly after the race, thereby resulting in a significant reduction of the total salivary IgA output. The salivary IgA concentration (mg IgA/ml) did not differ, but expressed as total salivary protein, a significant reduction was observed. This was on the account of the salivary protein concentration (mg protein/ml), which was significantly increased. In contrast to the IgA secretion, the salivary amylase activity was increased significantly after the race. Therefore, our data suggest that the exercise of a triathlon may decrease the level of IgA-mediated immune protection at the mucosal surface. As triathletes may during the race be exposed to micro-organisms present in the swimming water, a decreased IgA-mediated immunity during the race may pose triathletes at an increased risk of infections.

The authors used a longitudinal observational design, with repeated measures, to study the association between traffic-related air pollutants (i.e., nitric oxide, nitrogen dioxide, carbon monoxide, and Black Smoke) and respiratory symptoms. Subjects (N = 82) attended an elementary school in either Utrecht (i.e., urban children) or Bilthoven (i.e., suburban children). These two geographic areas differed with respect to levels of Black Smoke (means = 53 microg/m3 and 18 microg/m3, respectively). Levels of nitric oxide, nitrogen dioxide, carbon monoxide, and Black Smoke were consistently higher in Utrecht than in Bilthoven (mean daily ratios were 8, 1.5, 1.8, and 2.7, respectively). The authors compared mean levels of short-term effects of the aforementioned air pollutants on suburban and urban children. Urban children had higher mean levels (p = .05) of interleukin-8 (32%), urea (39%), uric acid (26%), albumin (15%), and nitric oxide metabolites (21%) in nasal lavage than did suburban children. Peak expiratory flow, exhaled nitric oxide levels, and nasal markers were associated with levels of particulate matter with diameters less than or equal to 10 microm, Black Smoke, nitrogen dioxide, and nitric oxide. With respect to per-unit increases in air pollution, urban children had more increased peak expiratory flow, higher levels of exhaled nitric oxide, and more increased release of uric acid, urea, and nitric oxide metabolites than suburban children. In summary, urban children had increased levels of inflammatory nasal markers, and their responses were more pronounced than were the suburban children's responses to the same increments of air pollution.

Background Exposure to microbial agents in the composting industry may cause work related airway inflammation. Nasal lavage (NAL) has been proposed as a noninvasive method to assess such effects in population studies. Methods Pre‐ and post‐shift NAL were performed in the workers of a compost plant visited in 1995 (n = 14) and 1996 (n=15), of whom only four participated in both surveys. Total cells, cytokines and other inflammation markers were measured in NAL fluid, and pre‐shift levels and post/pre concentration ratios were compared with NAL results obtained in the same periods in 10 and 9 controls, respectively, and with levels of airborne exposure to microbial agents endotoxin and β(1,3)‐glucan as measured in personal air samples. Results Job‐title specific exposure levels in the first survey ranged from 75 to 527 EU/m3 for endotoxin and from 0.54 to 4.85 μg/m3 for β(1,3)‐glucan. In the second survey these values were lower, 29–285 EU/m3 and 0.36–4.44 μg/m3, respectively. In the first survey pre‐shift NAL concentrations of total cells, MPO, IL‐8, NO and albumin were significantly (1.1–4.8 fold) higher in compost workers than in controls. Post/pre ratios for various markers were significantly (1.2–3.2 fold) higher in compost workers in both surveys. NAL cells were mainly neutrophils, while eosinophils were only incidentally observed. A weak relation with exposure was found for pre‐shift levels of MPO, uric acid and urea in the first survey. Conclusions Occupational exposure of compost workers may cause acute and possibly (sub‐)chronic inflammatory reactions in the upper airways, presumably induced by non‐allergenic pro‐inflammatory agents like endotoxins and β(1,3)‐glucans. Am. J. Ind. Med. 37:459–468, 2000. © 2000 Wiley‐Liss, Inc.

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The authors sought to determine which air pollutant is responsible for the increase in exhaled nitric oxide observed in healthy subjects. Exhaled nitric oxide was measured in 16 nonsmoking healthy subjects on 14 workdays, during which there were varying air-pollution levels. Contamination of samples by ambient nitric oxide was excluded. The baseline value of exhaled nitric oxide, determined at times when outdoor air pollution was low, ranged from 7 to 43 ppb (mean = 28+/-5 ppb). The daily value of exhaled nitric oxide (range = 5-60 ppb) was associated positively with ambient carbon monoxide (r = .85) and nitric oxide (r = .81). Exposure during the morning hours to high levels of outdoor pollution was associated with increased exhaled nitric oxide (i.e., 50% above baseline), which persisted for up to 5 h (i.e., 32% above baseline). These results indicated that exhaled nitric oxide levels represent a useful biomonitor of individual exposure to air pollutants.