Sensory irritation of acetic acid, hydrogen peroxide, peroxyacetic acid and their mixture in mice.

The expiratory bradypnoea indicative of upper airway irritation in mice was evaluated during a period of 60 min of oronasal exposure to acetic acid, hydrogen peroxide and peroxyacetic acid vapours. The airborne concentration resulting in a 50% decrease in the respiratory rate of mice (RD50) was calculated for each chemical. The concentration-response curves of acetic acid, hydrogen peroxide and peroxyacetic acid had similar slopes. The results did however show that the three chemicals had different irritant potencies. The RD50 values of acetic acid, hydrogen peroxide and peroxyacetic acid were 227, 113 and 5.4 p.p.m. respectively. Moreover, a mixture containing 53% acetic acid, 11% hydrogen peroxide and 36% peroxyacetic acid had an RD50 of 10.6 ppm, 3.8 ppm being peroxyacetic acid, which is 1.4 times lower than the theoretical value estimated from the fractional concentrations and the respective RD50s of the individual components. On the basis of a TLV-STEL (threshold limit value for short-term exposure limit) equal to 0.1 RD50, the TLV-STELs for acetic acid, hydrogen peroxide and peroxyacetic acid should not exceed 20, 10 and 0.5 p.p.m. respectively. On the basis of a TLV-TWA (time-weighted average) equal to 0.03 RD50, the TLV-TWAs for these same chemicals should not exceed 5, 3 and 0.2 p.p.m. respectively. Finally, these values and existing TLVs in Europe and the USA are compared.

Not only training but also exposure to chlorinated compounds generates a response to oxidative stimuli in swimmers.

Relations between exposure to chlorinated compounds and biological markers of response to oxidative stimuli were investigated in swimmers, taking into account the effect of training. Twenty-two male swimmers aged 15-25 years were surveyed twice. Prevalence of irritant symptoms and asthma and number of hours of training were reported. Exposure to nitrogen trichloride (NCl3) and blood response to oxidative stimuli [catalase, superoxide dismutase (Cu2+/Zn2+ SOD), glutathione peroxidase (GSH-Px) activities and ceruloplasmin, ferritin and total antioxidant concentrations] were measured. Univariate analyses were completed by multivariate analyses. High prevalences of irritant symptoms and asthma were found. Multivariate analysis confirmed the results of the univariate analyses and showed that Cu2+/Zn2+ SOD activity was increased by exposure and by training (P = 0.01, P = 0.0001, respectively). Erythrocyte GSH-Px was decreased, whereas plasma GSH-Px was increased by exposure (P = 0.002, P = 0.002). No other association was found. Higher irritant symptoms and increases in the activities of erythrocyte Cu2+/Zn2+ SOD and of plasma GSH-Px with exposure support the hypothesis that the production of reactive oxygen species is not only related to training but also to exposure to chlorinated compounds. Other athletes tend to have respiratory problems such as asthma, but the exposure to chlorinated compounds may increase the respiratory disease among swimmers.