Cytogenetic biomonitoring of Indian women cooking with biofuels: Micronucleus and chromosomal aberration tests in peripheral blood lymphocytes

Abstract

India currently has the largest number of indoor air pollution-related health problems in the world, with three-quarters of its households burning wood, cowdung, or crop residues ("traditional" biomass fuels) for cooking, and the remainder using kerosene and relatively clean-burning liquefied petroleum gas (LPG). Combustion of these fuels produces various pollutants that may cause serious health effects in exposed populations. In this study, the micronucleus (MN) and chromosomal aberration (CA) assays were used to evaluate the relative amounts of DNA damage produced by the use of these cooking fuels. Cytogenetic evaluation of 179 female subjects showed a significant increase in both MN and CA frequency in blood lymphocytes from users of biomass-fuels in comparison to lymphocytes from LPG users (used as a reference population). The relative MN and CA frequencies for the users of the various fuels decreased in the order cowdung > cowdung/wood >/= wood > kerosene >/= LPG. Further, the results indicated an effect of subject age, and the duration of exposure on the MN and CA frequencies in biomass fuel users. Age had no significant effects on the genotoxicity responses in subjects with </=10 years of exposure to either biomass fuels or LPG, but in subjects using biomass fuels for >10 years, CA and MN frequencies were higher in older individuals (>30 years of age) than younger subjects. Regardless of age, subjects burning biomass fuels had higher MN and CA frequencies than LPG users only when exposures were of at least 5 years duration. These results indicate that burning biomass-based fuels increases the frequency of cytogenetic alterations in blood lymphocytes of exposed populations, possibly because of exposure to the various noxious gases and toxic substances present in biomass fuels. These cytogenetic markers could be used in the field to assess the genotoxic consequences of burning various cooking fuels and for early detection of genetic abnormalities in people exposed to various pollutants and toxicants.

DNA damage in lymphocytes of rural Indian women exposed to biomass fuel smoke as assessed by the Comet assay

“…The results of this study, along with the results of other studies conducted on rural populations exposed to BMF smoke [Kato et al, 2004;Musthapa et al, 2004], may help explain the higher incidence of cancer among people using BMFs. It may be relevant to conduct an epidemiological study investigating any correlation between DNA damage levels and lung cancer incidence in rural Indian women exposed to BMF smoke.…”

“…Since the Comet assay is normally considered to detect only the most recent exposure, no significant difference was observed in the present study with respect to the duration of exposure. In comparison with a reference group using LPG, an increase in MN and CA frequency was observed in women using kerosene, but these increases were less than for women using wood and cow dung cakes as their source of cooking fuel [Musthapa et al, 2004]. In our study, differentiation between BMF types was not possible as the volunteers were using both wood and cow dung cakes as cooking fuel; however, a significant increase in DNA damage was observed in the BMF users.…”

“…Our study demonstrates an increased level of DNA damage in BMF users. Musthapa et al [2004] have shown an increase in the micronucleus (MN) and chromosomal aberration (CA) frequencies for Indian women using BMF relative to LPG users. They showed an exposure-dependent increase in the frequency of micronuclei and CA, indicating a cumulative effect of exposure.…”

Effects and mechanisms of kerosene use-related toxicity

“…In another study, cytogenetic alterations in blood lymphocytes of exposed populations to combustion of biomass-based fuels including kerosene was also reported [83]. The various noxious gases and toxic substances present in biomass fuels was implicated in this study to be the possible agents causing the genotoxic effects.…”

Enhanced Bioremediation of Polycyclic Aromatic Hydrocarbons by Environmentally Friendly Techniques

“…These covalent DNA adducts are thought to be carcinogenic and toxic. Significant DNA damage in lymphocytes of women exposed to PAHs-containing fuel smoke was detected by the comet assay or micronucleus test (40,41). Besides humans, genotoxicity of pollutants containing PAHs to other species such as fish was also measured with both comet assay and micronucleus (MN) test (42).…”