Nilmara de Oliveira Alves

Genotoxicity and composition of particulate matter from biomass burning in the eastern Brazilian Amazon region

In the present study Tradescantia pallida micronucleus (Trad-MCN) bioassay was used to assess the genotoxicity of particulate matter with a mass median aerodynamic diameter less than 10 μm (PM₁₀) in Tangara da Serra (MT), a Brazilian Amazon region that suffers the impact of biomass burning. The levels of PM (coarse and fine size fractions) and black carbon (BC) collected were also measured. Furthermore, the alkanes and polycyclic aromatic hydrocarbons (PAHs) were identified and quantified in the samples taken during the burning period by gas chromatography with flame ionization detection (GC-FID). The PM and BC results for both fractions indicate a strong correlation (p < 0.001). The analysis of alkanes indicates an anthropic influence. Retene was the most abundant PAH found, an indicator of biomass burning, and 12 other PAHs considered to be potentially mutagenic and/or carcinogenic were identified in this sample. The Trad-MCN bioassay showed a significant increase in micronucleus frequency during the period of most intense burning, possibly related to the mutagenic PAHs that were found in such extracts. This study demonstrated that Trad-MCN was sensitive and efficient in evaluating the genotoxicity of organic compounds from biomass burning. It further emphasizes the importance of performing chemical analysis, because changes in chemical composition generally have a negative effect on many living organisms. This bioassay (ex situ), using T. pallida with chemical analysis, is thus recommended for characterizing the genotoxicity of air pollution.

Genetic damage of organic matter in the Brazilian Amazon: A comparative study between intense and moderate biomass burning

BACKGROUND The biomass burning that occurs in the Amazon region has an adverse effect on environmental and human health. However, in this region, there are limited studies linking atmospheric pollution and genetic damage. OBJECTIVE We conducted a comparative study during intense and moderate biomass burning periods focusing on the genetic damage and physicochemical analyses of the particulate matter (PM). METHOD PM and black carbon (BC) were determined; organic compounds were identified and quantified using gas chromatography with flame ionization detection, the cyto-genotoxicity test was performed using two bioassays: cytokinesis-block micronucleus (CBMN) in A549 cells and Tradescantia pallida micronucleus (Trad-MCN) assay. RESULTS The PM10 concentrations were lower than the World Health Organization air quality standard for 24h. The n-alkanes analyses indicate anthropogenic and biogenic influences during intense and moderate biomass burning periods, respectively. Retene was identified as the most abundant polycyclic aromatic hydrocarbon during both sampling periods. Carcinogenic and mutagenic compounds were identified. The genotoxic analysis through CBMN and Trad-MCN tests showed that the frequency MCN from the intense burning period is significantly higher compared to moderate burning period. CONCLUSIONS This is the first study using human alveolar cells to show the genotoxic effects of organic PM from biomass burning samples collected in Amazon region. The genotoxicity of PM can be associated with the presence of several mutagenic and carcinogenic compounds, mainly benzo[a]pyrene. These findings have potential implications for the development of pollution abatement strategies and can minimize negative impact on health.

Before the first breath: prenatal exposures to air pollution and lung development.

Various environmental contaminants are known to impair the growth trajectories of major organs, indirectly (gestational exposure) or directly (postnatal exposure). Evidence associates pre-gestational and gestational exposure to air pollutants with adverse birth outcomes (e.g., low birth weight, prematurity) and with a wide range of diseases in childhood and later in life. In this review, we explore the way that pre-gestational and gestational exposure to air pollution affects lung development. We present results in topics underlining epidemiological and toxicological evidence. We also provide a summary of the biological mechanisms by which air pollution exposure possibly leads to adverse respiratory outcomes. We conclude that gestational and early life exposure to air pollutants are linked to alterations in lung development and function and to other negative respiratory conditions in childhood (wheezing, asthma) that may last into adulthood. Plausible mechanisms encompass changes in maternal physiology (e.g., hypoxia, oxidative stress and inflammation) and DNA alterations in the fetus. Evidence for pre-gestational and gestational effects on the lung is scarce compared with that on early life exposure and further studies are needed. However, the suggested mechanisms are credible and the evidence of pre-gestational and gestational air pollution exposure is robust for adverse birth outcomes. Air pollutants might change lung developmental trajectories of the unborn child predisposing it to diseases later in life highlighting the urgent need for controls on urban air pollution levels worldwide.

Disentangling vehicular emission impact on urban air pollution using ethanol as a tracer

The Sao Paulo Metropolitan Area is a unique case worldwide due to the extensive use of biofuel, particularly ethanol, by its large fleet of nearly 8 million cars. Based on source apportionment analysis of Organic Aerosols in downtown Sao Paulo, and using ethanol as tracer of passenger vehicles, we have identified primary emissions from light-duty-vehicles (LDV) and heavy-duty-vehicles (HDV), as well as secondary process component. Each of those factors mirror a relevant primary source or secondary process in this densely occupied area. Using those factors as predictors in a multiple linear regression analysis of a wide range of pollutants, we have quantified the role of primary LDV or HDV emissions, as well as atmospheric secondary processes, on air quality degradation. Results show a significant contribution of HDV emissions, despite contributing only about 5% of vehicles number in the region. The latter is responsible, for example, of 40% and 47% of benzene and black carbon atmospheric concentration, respectively. This work describes an innovative use of biofuel as a tracer of passenger vehicle emissions, allowing to better understand the role of vehicular sources on air quality degradation in one of most populated megacities worldwide.

0370 Systematic review and meta-analysis of occupational exposure to styrene and lung cancer

Styrene is widely used in industrial settings, leading to important occupational exposure. Currently it is classified by IARC as “possibly carcinogenic to humans” based on limited evidence of an association with lymphohaematopoietic cancers. Several recent studies suggest increased risk of lung cancer may be associated with exposure to styrene. We conducted a systematic search and a meta-analysis of epidemiologic studies of exposure to styrene and incidence or mortality of lung cancer. Of 167 papers retrieved, 50 were found to provide pertinent data after screening the abstracts; 42 of these were occupational cohort studies conducted in 3 main work settings: chemical production, reinforced plastics manufacturing, and styrene-butadiene rubber production. There was significant overlap in the populations among published papers, which reported data from 7 separate cohorts and one pooled international cohort, some parts of which were also published separately. Meta-analysis showed an excess risk of lung cancer among workers ever exposed to styrene (RR 1.14, 95% CI 1.04–1.24, I263%). The association was stronger when the analysis was limited to the reinforced plastics industry, where co-exposures are less important than in other industries (RR 1.20, 95% CI 1.10–1.31, I272%). Meta-analysis of exposure-response relations in the subset of studies that reported quantitative or categorical exposure data are ongoing and will be reported.

How can ecological urbanism promote human health

This special issue of URBE dedicated to Ecological Urbanism focuses on the role architects, landscape designers and urban planners can play in promoting healthier cities in Latin America. In this paper, we survey some of the empirical evidence that links the built environment with particular health outcomes. For many centuries, urban settlements were associated with adverse health outcomes, especially related to untreatable epidemics. As the science of disease transmission developed throughout the nineteenth century, the infrastructure of cities was transformed to promote improved public health. Significant gains were made, but in much of the world – Latin America included – urban health still remains a major challenge, all the more so as drug resistant strains of disease have become more prevalent. We believe Ecological Urbanism offers a promising framework for addressing these challenges. Distinguished by its integrated, multi-disciplinary foundation, Ecological Urbanism directly links both population and habitat health. This creates a natural opportunity for the design professions to play a more consequential role in shaping the health of urban settlements and, by extension, the regions they center.