Biomass burning particles in the Brazilian Amazon region: Mutagenic effects of nitro and oxy-PAHs and assessment of health risks☆
Graphical abstract
Introduction
The Amazon represents over half of the remaining tropical rain forests on the planet and contains one of the largest biodiversity in the world. Further, it corresponds to 61% of the area of Brazil (Malhi et al., 2008). Deforestation and land use have changed about 18% of the original tropical rain forest, mostly in the southern and western Amazonia. The land is used mainly for establishing pastures and preparing for crops, consequently causing many alterations in atmospheric dynamics (Artaxo et al., 2013). Interestingly, most of the forest fire hotspots in the Brazilian Amazon are located in an area of approximately 500,000 km2, with a population of over 10 million, known as the deforestation arc (de Oliveira Alves et al., 2015).
In October 2013, the International Agency for Research on Cancer (IARC) classified outdoor air pollution as carcinogenic to humans (Group 1) (IARC, 2016). In addition, IARC considers indoor emissions from household combustion of biomass fuel (primarily wood) as probably carcinogenic to humans (Group 2A) (IARC, 2010). Particulate matter (PM) is a heterogeneous mixture of chemicals that changes in space and time according to the emission source, and it is considered one of the main air pollutants. PM, with adsorbed chemical species such as polycyclic aromatic hydrocarbons (PAHs) and other mutagenic compounds, is suspected to increase the risk of human lung cancer and cardiovascular diseases (Brown et al., 2013, Raaschou-Nielsen et al., 2013, International Agency for Research on Cancer, 2013). The PAHs are formed by incomplete combustion or pyrolysis of organic material, together with their nitrated (nitro-PAHs) and oxygenated (oxy-PAHs) derivatives, represent one of the largest contributors to the biological effects of PM (Boström et al., 2002, Kelly and Fussell, 2012, Nemmar et al., 2013).
Many of the biological effects of PAHs, including mutagenesis and carcinogenesis, are believed to be mediated by activation of a series of enzymatically-catalyzed reactions to form their active metabolites. The mutagenic potential of PAHs is probably associated with the structural differences between DNA adducts and the consequent effects of their removal by DNA repair mechanisms (Boström et al., 2002, Jarvis et al., 2014). It is speculated that nitro- and oxy-PAHs are more mutagenic than unsubstituted PAHs because of their ability to act as direct mutagens; however, such quantification of risk is limited by sparse availability of toxicological data (Fu, 1990, Jung et al., 1991, Jariyasopit et al., 2014a, Jariyasopit et al., 2014b, Tomaz et al., 2016, Bandowe and Meusel, 2017).
The combination of chemical-analytical methods, along with specific extraction strategies, and short-term bioassays has been successfully used to evaluate effects of a variety of mutagenic compounds in complex environmental samples such as air (Kessler et al., 2012, Jarvis et al., 2013, Palacio et al., 2016). Cell-based bioassays that target relevant biological endpoints complement chemical analysis for environmental quality assessment (Escher et al., 2014). Many mutagenicity assays, such as Salmonella/microsome test (Umbuzeiro et al., 2008a, Alves et al., 2016), micronuclei analysis using plants as Tradescantia pallida (de Oliveira Alves et al., 2011, de Oliveira Galvão et al., 2014), human lung cell lines (de Oliveira Alves et al., 2014), and exfoliated buccal cells from exposed human populations (Bruschweiler et al., 2014, Wultsch et al., 2015, de Oliveira Galvão et al., 2017), have been used to evaluate the effects of different pollutants emitted by biomass burning. The exposure to fine particulate matter (PM2.5) generated in the Amazon region was reported to contribute to an increased micronuclei frequency in exfoliated buccal mucosa cells from schoolchildren (Sisenando et al., 2012).
Recently, de Oliveira Alves et al. (2015) determined the human health risk associated with exposure to PAHs emitted due to burning of biomass in western Amazon. The estimated cancer risk calculated during the dry seasons (17 × 10−5) exceeded the WHO health-based guideline (8.7 × 10−5). These facts point out the need to understand mutagenic mechanisms associated with the exposure to emissions from Amazon biomass burning.
The Salmonella/microsome test has long been used to detect potentially mutagenic environmental compounds. It is a short-term bacterial test that is able to detect mutagens that may directly alter the DNA, using selected mutant strains of Salmonella enterica serovar Typhimurium2 (Mortelmans and Zeiger, 2000). In environmental studies, TA98 and TA100 strains are usually employed for the detection of frameshift and basepair mutagenic activity, respectively. More recently developed strains with different metabolic capacities such as YG1041 and YG1042, with enhanced nitroreductase and acetyl transferase activities have been adopted in air pollution monitoring of specific classes of PAHs present in environmental samples (Claxton et al., 2004, DeMarini et al., 2004, Umbuzeiro et al., 2014). However, the Salmonella/microsome assay is able to detect solely point mutations. The inclusion of a test that detects chromosome damage is, therefore, a good strategy to supplement the information on the mutagenic hazards of a substance or complex mixture (Thybaud et al., 2007, Kirkland et al., 2011).
The cytokinesis-block micronucleus assay (CBMN) is a well-established in vitro genetic toxicology assay and has become an accepted standard method to assess the genotoxic hazard of chemicals (OECD, 2016). This protocol has been used in environmental studies investigating air quality with several different cell lines, as reported by Bocchi et al. (2016) and de Oliveira Alves et al. (2014) for A549 cells; León-Mejía et al. (2016) for V79 cells; Xin et al. (2014) for HepG2 cells; and Zhai et al. (2012) for HBE cells. Micronuclei (MN) are biomarkers of mutagenicity that may originate from whole chromosomes that are unable to migrate to the poles during the anaphase stage of cell division and/or acentric chromosome fragments, both induced by aneugenic or clastogenic substances, respectively (Kirsch-Volders et al., 2011, Kirsch-Volders et al., 2014). The cytome approach of this assay provides information about chromosome breakage and/or loss (e.g., MN), gene amplification (e.g., nuclear buds) and chromosome rearrangement, as dicentric chromosomes (e.g., nucleoplasmic bridges) (Kirsch-Volders et al., 2011, Kirsch-Volders et al., 2014).
The aims of this study were: i) to identify and quantify nitro-PAHs and oxy-PAHs present in the PM emitted from burning of biomass in the Amazon region; ii) to estimate the excess lifetime cancer risk for the exposed population; and iii) to assess the in vitro mutagenic effects of extractable organic matter collected during the periods of moderate and intense biomass burning, comparing the sensitivity of a prokaryote (Salmonella/microsome test) and a eukaryote (CBMN with human lung cells) mutagenicity assays.
Section snippets
Air sampling and solvent extraction
PM10 fraction was collected from the rural area of Porto Velho, state of Rondônia, in the western part of the Amazon region. The sampling site (8.69° S, 63.87° W) is located in a region with large land use and associated regional biomass burning (de Oliveira Alves et al., 2015). The sampling conditions and instrumentation details were previously described by Brito et al. (2014). Sample collection was conducted during two distinct periods: intense biomass burning – dry season
Airborne PM and EOM concentrations
Time series of PM10, EOM, and fire spots are shown in Fig. 1. In accordance with the results obtained with the MODIS sensor, larger number of fire spots occurred between July and October/2011 (INPE, 2014). Higher peaks of PM10 concentrations were observed during intense biomass burning, with concentrations reaching close to 60 μg/m3.
Table 1 shows the number of filters, total collected air volume, concentration of PM10, EOM and PAHs for each of the two samples tested for mutagenicity. The
Discussion
In this study, we quantified the nitro-PAHs and oxy-PAHs present in the emitted PM from the Amazon biomass burning and estimate excess lifetime cancer risk as well as the in vitro mutagenic effects of the extractable organic matter. We also compared the sensitivity of a prokaryote (Salmonella/microsome test) and a eukaryote (CBMN with human lung cells) mutagenicity assays.
PM from burning of biomass can substantially degrade air quality, leading to adverse effects on human health (Jacobson
Conclusions
This study addressed the effects of extractable organic matter of PM emitted from Amazon biomass burning on DNA damage and showed its mutagenic activity using different bioassays. The Salmonella/microsome test was considerably more sensitive to the organic matter in comparison with the CBMN using human lung cells mainly for the intense burning period samples. This was the first study to assess the mutagenicity of the samples collected in Amazon region using Salmonella/microsome test. The data
Acknowledgments
The authors would like to thank the financial support from the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq - MCT/CNPq Proc. Univ. 471033/2011-1), and Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES). P.A. acknowledge funding from Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP proc. 2013/05014-0), S.S.H. to Brazilian Network on Global Climate Change Research funded by CNPq proc. 550022/2014-7, FINEP proc. 01.13.0353.00 and P.C.V. the INCT
References (105)
- et al.
Exposure to polycyclic aromatic hydrocarbons in urban environments: health risk assessment by age groups
Environ. Pollut.
(2014) - et al.
An empirical approach to the statistical analysis of mutagenesis data from the Salmonella test
Mutat. Res.
(1982) - et al.
Characterization of urban aerosol: seasonal variation of mutagenicity and genotoxicity of PM2.5, PM1 and semi-volatile organic compounds
Mutat. Res. Toxicol. Environ. Mutagen
(2016) - et al.
Nature and sources of particle associated polycyclic aromatic hydrocarbons (PAH) in the atmospheric environment of an urban area
Environ. Pollut.
(2013) - et al.
Source apportionment of atmospheric PM2.5-bound polycyclic aromatic hydrocarbons by a PMF receptor model. Assessment of potential risk for human health
Environ. Pollut.
(2014) - et al.
Health risk assessment on human exposed to environmental polycyclic aromatic hydrocarbons pollution sources
Sci. Total Environ.
(2006) - et al.
The genotoxicity of ambient outdoor air, a review: Salmonella mutagenicity
Mutat. Res. - Rev. Mutat. Res.
(2004) - et al.
Genetic biomonitoring of an urban population exposed to mutagenic airborne pollutants
Environ. Int.
(2009) - et al.
Improved GC/MS methods for measuring hourly PAH and nitro-PAH concentrations in urban particulate matter
Atmos. Environ.
(2006) - et al.
Genotoxicity and composition of particulate matter from biomass burning in the eastern Brazilian Amazon region
Ecotoxicol. Environ. Saf.
(2011)
Genetic damage of organic matter in the Brazilian Amazon: a comparative study between intense and moderate biomass burning
Environ. Res.
Biomass burning in the Amazon region: aerosol source apportionment and associated health risk assessment
Atmos. Environ.
Cashew nut roasting: chemical characterization of particulate matter and genotocixity analysis
Environ. Res.
Characterization of the particulate matter and relationship between buccal micronucleus and urinary 1-hydroxypyrene levels among cashew nut roasting workers
Environ. Pollut.
Human cell mutagenicity of oxygenated, nitrated and unsubstituted polycyclic aromatic hydrocarbons associated with urban aerosols
Mutat. Res.
Mutagenicity of 30 chemicals in Salmonella typhimurium strains possessing different nitroreductase or O-acetyltransferase activities
Mutat. Res. Toxicol.
Effect-based trigger values for in vitro bioassays: Reading across from existing water quality guideline values
Water Res.
The in vitro micronucleus technique
Mutat. Res. Mol. Mech. Mutagen
HUMN project: detailed description of the scoring criteria for the cytokinesis-block micronucleus assay using isolated human lymphocyte cultures
Mutat. Res. - Genet. Toxicol. Environ. Mutagen
Characterization of the A549 cell line as a type II pulmonary epithelial cell model for drug metabolism
Exp. Cell Res.
Relationships among direct-acting mutagenicity, nitro group orientation and polarographic reduction potential of 6-nitrobenzo[a]pyrene, 7-nitrobenz[a]anthracene and their derivatives
Mutat. Res. Lett.
Specificity and sensitivity of Salmonella typhimurium YG1041 and YG1042 strains possessing elevated levels of both nitroreductase and acetyltransferase activity
Mutat. Res.
Persistent activation of DNA damage signaling in response to complex mixtures of PAHs in air particulate matter
Toxicol. Appl. Pharmacol.
A simple modification of the Salmonella liquid-incubation assay. Increased sensitivity for detecting mutagens in human urine
Mutat. Res.
Size, source and chemical composition as determinants of toxicity attributable to ambient particulate matter
Atmos. Environ.
A bacterial bioreporter panel to assay the cytotoxicity of atmospheric particulate matter
Atmos. Environ.
A core in vitro genotoxicity battery comprising the Ames test plus the in vitro micronucleus test is sufficient to detect rodent carcinogens and in vivo genotoxins
Mutat. Res. Toxicol. Environ. Mutagen
Commentary: critical questions, misconceptions and a road map for improving the use of the lymphocyte cytokinesis-block micronucleus assay for in vivo biomonitoring of human exposure to genotoxic chemicals—a HUMN project perspective
Mutat. Res.
Revised methods for the Salmonella mutagenicity test
Mutat. Res.
Analytical methods in bioassay-directed investigations of mutagenicity of air particulate material
Mutat. Res. - Rev. Mutat. Res.
Organic composition of size segregated atmospheric particulate matter, during summer and winter sampling campaigns at representative sites in Madrid
Spain. Atmos. Res.
The Ames Salmonella/microsome mutagenicity assay
Mutat. Res.
Rapid colorimetric assay for cellular growth and survival: application to proliferation and cytotoxicity assays
J. Immunol. Methods
Evaluating the mutagenicity of the water-soluble fraction of air particulate matter: a comparison of two extraction strategies
Chemosphere
Toxicogenetic monitoring in urban cities exposed to different airborne contaminants
Ecotoxicol. Environ. Saf.
Air pollution and lung cancer incidence in 17 european cohorts: prospective analyses from the european study of cohorts for air pollution effects (ESCAPE)
Lancet Oncol.
Micronuclei induced by airborne particulate matter from Mexico City
Mutat. Res. - Genet. Toxicol. Environ. Mutagen
Contribution of l-nitropyrene to direct-acting Ames assay mutagenicities of diesel particulate extracts
Mutat. Res.
Genotoxic and inflammatory effects of organic extracts from traffic-related particulate matter in human lung epithelial A549 cells: the role of quinones
Toxicol. Vitr.
Airborne quinones induce cytotoxicity and DNA damage in human lung epithelial A549 cells: the role of reactive oxygen species
Chemosphere
Strategy for genotoxicity testing: hazard identification and risk assessment in relation to in vitro testing
Mutat. Res. Toxicol. Environ. Mutagen
Mutagenicity of nitro derivatives induced by exposure of aromatic compounds to nitrogen dioxide
Mutat. Res. Mutagen. Relat. Subj
One-year study of polycyclic aromatic compounds at an urban site in Grenoble (France): seasonal variations, gas/particle partitioning and cancer risk estimation
Sci. Total Environ.
Mutagenicity and DNA adduct formation of PAH, nitro-PAH, and oxy-PAH fractions of atmospheric particulate matter from São Paulo, Brazil
Mutat. Res. - Genet. Toxicol. Environ. Mutagen
Temporal variation of nitro-polycyclic aromatic hydrocarbons in PM10 and PM2.5 collected in Northern Mexico City
Sci. Total Environ.
Pollution characteristics, sources and lung cancer risk of atmospheric polycyclic aromatic hydrocarbons in a new urban district of Nanjing
China. J. Environ. Sci.
Characterization of PM2.5-bound nitrated and oxygenated PAHs in two industrial sites of South China
Atmos. Res.
PM10-bound polycyclic aromatic hydrocarbons: concentrations, source characterization and estimating their risk in urban, suburban and rural areas in Kandy, Sri Lanka
Atmos. Environ.
Mutagenicity profile of atmospheric particulate matter in a small urban center subjected to airborne emission from vehicle traffic and sugar cane burning
Environ. Mol. Mutagen
Environmental change and the carbon balance of Amazonian forests
Biol. Rev.
Cited by (73)
Potential source and health risks of black carbon based on MERRA-2 reanalysis data in a typical industrial city of North China Plain
2024, Journal of Environmental ManagementCharacterization of a new sustainable supramolecular solvent and application to the determination of oxy-PAHs in meat, seafood and fish tissues
2023, Food ChemistryCitation Excerpt :Despite of the need to elucidate the risk of the human exposure to oxy-PAHs, studies about their presence in environmental samples, and especially in food, is still limited. Results show that they are widely distributed in the atmosphere, water, soil and sediments at levels in the same order of magnitude than PAHs and up to 10 times higher than nitro-PAHs (Wei et al., 2015; Bandowe & Nkansah, 2016; De Oliveira Galvao et al., 2018). Table S1 shows reported levels in food, which range from few ng/g down to pg/g levels, together with details of the employed analytical methods for their determination.
Particulate matter fingerprints in biofuel impacted tunnels in South America's largest metropolitan area
2023, Science of the Total Environment