Pulmonary toxicity following exposure to a tile coating product containing alkylsiloxanes. A clinical and toxicological evaluation

Abstract

Context. coating products are widely used for making surfaces water and dirt repellent. however, on several occasions the use of these products has been associated with lung toxicity. Objective. in the present study, we evaluated the toxic effects of an aerosolized tile-coating product. Methods. Thirty-nine persons, who reported respiratory and systemic symptoms following exposure to the tile-coating product, were clinically examined. The product was analysed chemically and furthermore, the exposure scenario was reconstructed using a climate chamber and the toxicological properties of the product were studied using in vivo and by in vitro surfactometry. Results. The symptoms developed within few hours and included coughing, tachypnoea, chest pain, general malaise and fever. The physical examination revealed perihilar lung infiltrates on chest radiograph and reduced blood oxygen saturation. The acute symptoms resolved gradually within 1-3 days and no delayed symptoms were observed. By means of mass spectrometry and X-ray spectroscopy, it was shown that the product contained non-fluorinated alkylsiloxanes. The exposure conditions in the supermarket were reconstructed under controlled conditions in a climate chamber and particle and gas exposure levels were monitored over time allowing estimation of human exposure levels.Mice exposed to the product developed symptoms of acute pulmonary toxicity in a concentration-and time-dependent manner. The symptoms of acute pulmonary toxicity likely resulted from inhibition of the pulmonary surfactant function as demonstrated by in vitro surfactometry. Among these patients only a partial association between the level of exposure and the degree of respiratory symptoms was observed, which could be because of a high inter-individual difference in sensitivity and time-dependent changes in the chemical composition of the aerosol. Conclusion. Workers need to cautiously apply surface coating products because the contents can be highly toxic through inhalation, and the aerosols can disperse to locations remote from the worksite and affect bystanders.

An in vitro method for predicting inhalation toxicity of impregnation spray products

“…Therefore, mice were killed immediately after the recovery period by cervical dislocation. No acute fatalities were observed in our previous publications (Nørgaard et al, 2010Duch et al, 2014), however fatalities were documented with two waterbased products in the present study. We have no explanation for this except that this may be ascribed to the specific product formulation and thus may not have been preventable.…”

“…The observed effects were comparable to those found in live rats and indicated that the spray products damaged the surfactant film. We have shown inhibition of pulmonary surfactants using the Langmuir technique (Duch et al, 2014;Larsen et al, 2014) and the interactions have been demonstrated using porcine (HL-10 (Vermehren et al, 2006) and Curosurf ® (Bernhard et al, 2000)) as well as bovine (Alveofact ® (Gunther et al, 2002)) pulmonary surfactant formulations. Results from these relatively diverse pulmonary surfactant formulations were in overall agreement, suggesting that pulmonary surfactant inhibition is a robust and reliable endpoint.…”

“…Atelectasis may progress to tissue damage and edema, and product testing may cause lethal lung damage (Hubbs et al, 1997;Nørgaard et al, 2010;Pauluhn et al, 2008). We have recently shown that a tile-coating product, "Stain repellent super", which caused respiratory distress in 39 people in Greenland, also inhibits the function of pulmonary surfactant in vitro using the Langmuir balance, i.e., the classical method for studying lung surfactant properties (Duch et al, 2014), substantiating that this endpoint has relevance for effects in humans. "Stain repellent super" also induced acute pulmonary toxicity in mice similarly to the effects observed in the present study.…”

“…This method was recently used to identify that the main target of an impregnation product was surfactant protein-B (Larsen et al, 2004). Furthermore, the Langmuir technique allows assessment of impregnation products with a high boiling point (Duch et al, 2014). On the other hand, the Langmuir technique is time-consuming and requires relatively large amounts of pulmonary surfactant.…”

“…Both rats (Pauluhn et al, 2008), guinea pigs (Hubbs et al, 1997) and mice (Duch et al, 2014;Yamashita and Tanaka, 1995) are useful for this purpose. The mouse model used in the present study has previously been used to assess airway irritation potential of industrial chemicals (Alarie, 1973).…”