Exhaled breath condensate pH and FeNO as biomarkers of acute and chronic exposure to hazards at swine farms.

OBJECTIVE: The noninvasive biomarkers of respiratory impairment were assessed in 15 swine confinement (SC) workers and 9 respiratory healthy, nonsmoking volunteers (HV). METHODS: Spirometry, fraction of exhaled nitric oxide (FeNO), and exhaled breath condensate (EBC) pH were assessed in SC workers after one working shift and one working week and in HV after 5-hour exposure in SC. RESULTS: Half of the respiratory symptoms (in 8 of 15 SC workers) were work-related. Basal FeNO values were 7.5 ppb higher in the SC workers compared with HV. In the SC workers, EBC pH increased for 0.17 at the end of a working week (P < 0.001). In HV, 5-hour exposure in SC induced 8% drop in forced expiratory flow at 25% of the pulmonary volume (FEF25) (P = 0.008), EBC pH drop for 0.10 units (P = 0.003), and FeNO drop by 1.8 ppb (P = 0.047). CONCLUSIONS: EBC pH was suggested as a biomarker of acute airway acidification in HV, whereas the SC workers showed signs of the "healthy worker effect."

Response to thermal and physical strain during flashover training in Croatian firefighters.

Flashover training (FOT) for firefighters is a simulation of the flashover phenomenon under controlled conditions. This study assessed arterial blood pressure (BP) and its response to thermal and physical strain during FOT in 48 professional and 18 volunteer firefighters. A high prevalence of obesity (27%), basal hypertensive (53%) and prehypertensive (33%) BP values was found. FOT induced mild hyperthermia and physical strain (average increase of 1.1 °C in tympanic temperature and 61% of the maximal heart beat predicted for age). Compared to professional firefighters, FOT in the volunteers induced a higher increase in pulse (P = 0.050) and tympanic temperature (P = 0.025). Systolic BP did not vary significantly, and diastolic BP slightly decreased in both groups. Results confirm that FOT induced only physiological cardiovascular responses to thermal and physical strain in firefighters. High prevalence of obesity and elevated BP values indicate the need for better physical fitness and BP control among firefighters.

Exhaled breath condensate pH in adult Croatian population without respiratory disorders: how healthy a population should be to provide normative data?

The aim of this study was to obtain preliminary exhaled breath condensate (EBC) pH values for healthy adult Croatian subjects, and to evaluate criteria for defining respiratory health of population providing normal EBC pH values in epidemiologic studies. In 109 adults without a history of lower airway symptoms (AS), four groups were described by narrowing the definition of "health" down to 1) without lower AS; 2) without lower and upper AS; 3) without AS, with normal FEV(1) and bronchial normoreactivity; 4) without AS, with normal FEV(1), bronchial normoreactivity, normal total IgE, and with negative skin prick test. Median EBC pH values did not differ between the groups (7.72, 7.73, 7.73, 7.73), but as health criteria got stricter, we observed a slight, nonsignificant increase in minimal pH values (6.95, 7.10, 7.20, 7.37). Median EBC pH values with interquartile range in the total sample (7.72; 7.63 to 7.76) were within the range previously reported by other authors. They did not differ regarding sex, smoking habit and atopic status, and were not associated with age, FEV(1) or total IgE. The non-significant trend in EBC pH observed with stricter criteria of respiratory health and atopic status indicates the need for further research on criteria for defining healthy population in a larger sample.