Chronic inhalation of biomass smoke is associated with DNA damage in airway cells: involvement of particulate pollutants and benzene

Abstract

This study examined whether indoor air pollution from biomass fuel burning induces DNA damage in airway cells. For this, sputum cells were collected from 56 premenopausal rural women who cooked with biomass (wood, dung, crop residues) and 49 age-matched controls who cooked with cleaner liquefied petroleum gas. The levels of particulate matters with diameters of less than 10 and 2.5 µm (PM(10) and PM(2.5)) in indoor air were measured using a real-time aerosol monitor. Benzene exposure was monitored by measuring trans,trans-muconic acid (t,t-MA) in urine by HPLC-UV. DNA damage was examined by alkaline comet assay in sputum cells. Generation of reactive oxygen species (ROS) and level of superoxide dismutase (SOD) in sputum cells were measured by flow cytometry and spectrophotometry, respectively. Compared with controls, biomass users had 4 times higher tail percentage DNA, 37% more comet tail length and 5 times more Olive tail moment (p < 0.001) in inflammatory and epithelial cells in sputum, suggesting extensive DNA damage. In addition, women who cooked with biomass had 6 times higher levels of urinary t,t-MA and 2-fold higher levels of ROS generation concomitant with 28% depletion of SOD. Indoor air of biomass-using households had 2-4 times more PM(10) and PM(2.5) than that of controls. After controlling potential confounders, positive association was found between DNA damage parameters, particulate pollution, urinary t,t-MA and ROS. Thus, long-term exposure to biomass smoke induces DNA damage in airway cells and the effect was probably mediated, at least in part, by oxidative stress generated by inhaled particulate matter and benzene.

Biomarkers of oxidative stress and inflammation after wood smoke exposure in a reconstructed Viking Age house

“…It is possible that the type of combustion particles differ between the exposure circumstances. For instance, the studies from India are characterized by a relatively high exposure to indoor concentrations of benzene [Mukherjee et al, ]. We have previously observed a clear correlation between personal benzene exposure and oxidatively damaged DNA in PBMC of humans living in areas with high traffic intensity [Avogbe et al, ].…”

Indoor Air Contaminants and Their Impact on Respiratory Pathologies

“…50 It has recently been observed in sputum samples that there is deterioration in the DNA of individuals exposed to biomass smoke compared to those who use liquid gas for cooking, and it seems to be at least partially mediated by oxidative stress generated by the inhalation of particles and benzene. 51 There has also been a demonstrated carcinogen effect of coal smoke, which significantly increases the risk for LC in exposed people (OR: 2.55; 95% CI: 1.58-4.10). 37 The Cancer Prevention Study-II observed that exposure to radon levels higher than 148 Bq/m 3 (considered the tolerance threshold by the EPA) represented an increase of 34% (95% CI: 7-68) in the risk of dying from LC.…”

Coal Fly Ash Impairs Airway Antimicrobial Peptides and Increases Bacterial Growth

“…Reactive oxygen species (ROS) production in the airway had been linked to the presence of PM [22] which can generate ROS through oxidation on the surface of the particles, including CFA, which is shown to elicit ROS damage to DNA [23]. It has been reported that in cell culture, at concentrations of 100 µg/mL, CFA with LPS increases ROS [24].…”