Health consequences of disinfection against SARS-CoV-2: Exploring oxidative stress damage using a biomonitoring approach.

Individuals who get involved in the disinfection of public settings using sodium hypochlorite might suffer adverse health effects. However, scarce information is available on the potential oxidative stress damage caused at low concentrations typically used for disinfection. We aimed to assess whether exposure to sodium hypochlorite during the COVID-19 pandemic causes oxidative stress damage in workers engaged in disinfection tasks. 75 operators engaged in the disinfection of public places were recruited as the case group, and 60 individuals who were not exposed to disinfectant were chosen as the control group. Spot urine samples were collected before (BE) and after exposure (AE) to disinfectants in the case group. Likewise, controls provided two spot urine samples in the same way as the case group. Urinary malondialdehyde (MDA) levels were quantified by forming thiobarbituric acid reactive substances in the urine. In addition, the concentration of 8-hydroxy-2'-deoxyguanosine (8-OHdG) in the urine was determined using an ELISA kit. Results showed significant differences in the urinary levels of oxidative stress markers, where median 8-OHdG (AE case: 3.84 ± 2.89 µg/g creatinine vs AE control 2.54 ± 1.21 µg/g creatinine) and MDA (AE case: 169 ± 89 µg/g creatinine vs AE control 121 ± 47 µg/g creatinine) levels in case group AE samples were 1.55 and 1.35-times higher than the control group AE samples (P < 0.05), respectively. Besides, urinary levels of oxidative stress markers in AE samples of the case group were significantly higher than in BE samples (8-OHdG BE 3.40 ± 1.95 µg/g creatinine, MDA BE 136 ± 51.3 µg/g creatinine, P < 0.05). Our results indicated that exposure to even low levels of sodium hypochlorite used in disinfection practices might cause oxidative stress related damage. With this in mind, implementing robust protective measures, such as specific respirators, is crucial to reduce the health burdens of exposure to disinfectants.

Assessment of fungal bioaerosols and particulate matter characteristics in indoor and outdoor air of veterinary clinics.

Veterinary staff are frequently exposed to various occupational hazards. The present study was aimed to investigate the air characteristics of veterinary clinics in terms of fungal bioaerosols and particulate matters. Air samples were taken every six days from the operating room, examination room and outdoor air of three veterinary clinics in Shiraz, southwest Iran. The concentrations of fungal bio-aerosols ranged from 8.05 CFU/m 3 in the outdoor air of clinic B to 47.21 CFU/m 3 in the operating room of clinic A. The predominant fungal genera identified in the studied clinics were Penicillium and Aspergillus niger, respectively. The concentrations of PM2.5 ranged from 41.88 µg/m 3 in the operating room of clinic C to 60.31 µg/m 3 in the outdoor air of the same clinic. The corresponding values for PM10 ranged from 114.40 µg/m 3 in the operating room of clinic C to 256.70 µg/m 3 in the outdoor air of the same clinic. The results of this study showed a positive correlation between the concentration of fungal bioaerosols and relative humidity (p < 0.05; r = 0.622). Besides, a negative correlation was found between the concentration of fungal bioaerosols and temperature (p < 0.05; r = 0.369). To better assess the individual exposure of veterinarians and staff in veterinary clinics, tests including nasopharyngeal sampling are recommended.