Characteristics and assessing biological risks of airborne bacteria in waste sorting plant

Abbas Norouzian Baghani; Somayeh Golbaz; Gholamreza Ebrahimzadeh; Marcelo I Guzman; Mahdieh Delikhoon; Mehdi Jamshidi Rastani; Abdullah Barkhordari; Ramin Nabizadeh

doi:10.1016/j.ecoenv.2022.113272

Characteristics and assessing biological risks of airborne bacteria in waste sorting plant

Ecotoxicol Environ Saf. 2022 Mar 1:232:113272. doi: 10.1016/j.ecoenv.2022.113272. Epub 2022 Feb 1.

Authors

Abbas Norouzian Baghani¹, Somayeh Golbaz², Gholamreza Ebrahimzadeh³, Marcelo I Guzman⁴, Mahdieh Delikhoon⁵, Mehdi Jamshidi Rastani⁶, Abdullah Barkhordari⁷, Ramin Nabizadeh⁸

Affiliations

¹ Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran. Electronic address: abbas.jj.norozi@gmail.com.
² Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
³ Department of Environmental Health Engineering, Faculty of Health, Zabol University of Medical Sciences, Zabol, Iran.
⁴ Department of Chemistry, University of Kentucky, Lexington, KY 40506, USA. Electronic address: marcelo.guzman@uky.edu.
⁵ Department of Occupational Health Engineering, School of Public Health, Isfahan University of Medical Sciences, Isfahan, Iran. Electronic address: mahdieh.d2771@gmail.com.
⁶ Department of Occupational Health Engineering, School of Public Health, Shahroud University of Medical Sciences, Shahroud, Iran.
⁷ Department of Occupational Health Engineering, School of Public Health, Shahroud University of Medical Sciences, Shahroud, Iran; Environmental and Occupational Health Research Center, Shahroud University of Medical Sciences, Shahroud, Iran.
⁸ Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran; Center for Air Pollution Research (CAPR), Institute for Environmental Research (IER), Tehran University of Medical Sciences, Tehran, Iran. Electronic address: rnabizadeh@tums.ac.ir.

PMID: 35121253
DOI: 10.1016/j.ecoenv.2022.113272

Abstract

Examining the concentration and types of airborne bacteria in waste paper and cardboard sorting plants (WPCSP) is an urgent matter to inform policy makers about the health impacts on exposed workers. Herein, we collected 20 samples at 9 points of a WPCSP every 6 winter days, and found that the most abundant airborne bacteria were positively and negatively correlated to relative humidity and temperature, respectively. The most abundant airborne bacteria (in units of CFU m^-3) were: Staphylococcus sp. (72.4) > Micrococcus sp. (52.2) > Bacillus sp. (30.3) > Enterococcus sp. (24.0) > Serratia marcescens (20.1) > E. coli (19.1) > Pseudomonas sp. (16.0) > Nocardia sp. (1.9). The lifetime average daily dose (LADD) for the inhalation and dermal routes for the intake of airborne bacteria ranged from 3.7 × 10^-3 ≤ LADD_Inhalation ≤ 2.07 × 10¹ CFU (kg d)^-1 and 4.75 × 10^-6 ≤ LADD_Dermal ≤ 1.64 × 10^-5 CFU (kg d)^-1, respectively. Based on a sensitivity analysis (SA), the concentration of airborne bacteria (C) and the exposure duration (ED) had the most effect on the LADD_Inhalation and LADD_Dermal for all sampling locations. Although the Hazard Quotient of airborne bacteria was HQ < 1, an acceptable level, the indoor/outdoor ratio (1.5 ≤ I/O ≤ 6.6) of airborne bacteria typically exceeded the threshold value (I/O > 2), indicating worker's exposure to an infected environment. Therefore, in the absence of sufficient natural ventilation the indoor ambient conditions of the WPCSP studied should be controlled by supplying mechanical ventilation.

Keywords: Airborne bacteria; Hazard quotient; Health risk assessment; Indoor/outdoor bacteria; Paper and cardboard.

MeSH terms

Air Microbiology*
Air Pollution, Indoor* / analysis
Bacteria
Environmental Monitoring
Escherichia coli
Fungi
Humans
Occupational Exposure*
Refuse Disposal*
Seasons