Multiple exposure pathways and health risk assessment of potentially harmful elements for children and adults living in a coal region in Brazil

Human health risk assessment of metals in soil samples of a Brazilian city with a historic contamination complex

Rio Grande is a city located on a narrow industrialized and urbanized Brazilian peninsula, characterized by wetlands. Due to population growth, numerous urban backfilled regions were built to expand the territorial area of the city. Currently, more than 60% of the central area of the city comes from the grounding of wetlands. The material used for the expansion of the territory had a history of contamination from metals from the tannery and textile industries (mainly Hg) and urban solid waste. In addition to past sources, the city has an active industrial complex with fertilizer, petrochemical, and grain industries. This study evaluated the risks to human health caused by metals (Hg, Fe, Ni, Cr, Cu, Pb, and Zn) in original soils and backfills, considering the oral, inhalation, and dermal routes of exposure for children and adults using the tool human health risk assessment (HHRA) proposed methodology by USEPA. A total of 63.81% of the original soil samples and 57.14% of the backfill soil samples showed a non-carcinogenic risk (HInc>1) for at least one evaluated metal. Still, approximately 10% of the samples presented carcinogenic risk when the Cr was considered in the hexavalent form. The dermal (Hg, Ni, and Cr) and oral (Fe, Cu, and Zn) exposure routes had the greatest contribution to the total risk. The non-carcinogenic risk for Hg, Cr(VI), and Pb was heterogeneously distributed between the original soils and backfills and associated with the proximity to some pollution sources. Given the complexity of historical occupation in the municipality and the increasing industrialization, both the original areas and the backfills should be included in the risk management strategy to minimize risks.

Correlation of Elemental Transfer, Bioactive Compounds and Antioxidant Activity on Lactuca sativa L. Grown in Soil with Functionalized CNT and HMs

While heavy metals (HM) have been considered in recent decades to be the most common and problematic pollutants, the expansion of the list of pollutants due to the active use of carbon nanotubes (CNT) raises new questions about the benefit and harm of HM released to nature individually or fixed on CNT walls. A pot experiment was conducted to compare the effect of two classes of potential pollutants-metal salts of Pb, Mn, Cu, Zn, Cd, and Ni; and functionalized CNTs with COOH, MnO2, Fe3O4, and MnO2-Fe3O4-applied in soil, on the elemental transfer, the bioactive compounds accumulation, and the antioxidant activity in lettuce. While CNTs mainly increased the elemental transfer from soil to leaves, HM salts strongly obstructed it. In the presence of CNTs, the antioxidant activity in lettuce leaves correlated with the transfer of elements from soil to root and from root to leaves. The excess of HMs in soil induced a greater variation of the polyphenols quantity and antioxidant activity than the excess of CNTs. It might be assumed that lettuce perceived HMs as a more aggressive stressor than CNTs and more strongly activated the defense mechanism, showing the reduction of the element transfer and enhancing of total polyphenol production and antioxidant activity.

Trimester-specific effects of maternal exposure to single and mixed metals on cord serum inflammatory cytokines levels: A prospective birth cohort study

BACKGROUND

Cord blood inflammatory cytokines are vital in early-life programming. An increasing number of studies concern the effect of maternal exposure to different metal elements during pregnancy on inflammatory cytokines, but limited studies have explored the association between maternal exposure to mixed metals and cord blood inflammatory cytokine levels.

METHODS

We measured serum concentrations of vanadium (V), copper (Cu), arsenic (As), cadmium (Cd), and barium (Ba) in the first, second, and third trimesters and eight cord serum inflammatory cytokines (IFN-γ, IL-1β, IL-6, IL-8, IL-10, IL-12p70, IL-17A, and TNF-α) in 1436 mother-child dyads from the Ma'anshan Birth Cohort. Generalized linear models and Bayesian kernel machine regression (BKMR) were performed to assess the association of single and mixed metal exposure during each trimester with cord serum inflammatory cytokine levels, respectively.

RESULTS

Regarding metal exposure in the first trimester, V was positively associated with TNF-α (β = 0.33, 95 % CI: 0.13, 0.53); Cu was positively associated with IL-8 (β = 0.23, 95 % CI: 0.07, 0.39); Ba was positively associated with IFN-γ and IL-6; As was negatively associated with IFN-γ and IL-17A; and Cd was negatively associated with IFN-γ, IL-1β, IL-12p70, IL-17A, and TNF-α. BKMR revealed that exposure to metal mixtures in the first trimester was positively associated with IL-8 and TNF-α but negatively associated with IL-17A. Moreover, V contributed the most to these associations. Interaction effects were observed between Cd and As and between Cd and Cu with IL-8, and between Cd and V with IL-17A. Among males, As decreased inflammatory cytokines; among females, Cu increased inflammatory cytokine levels, whereas Cd decreased inflammatory cytokine concentrations.

CONCLUSIONS

Maternal exposure to metal mixtures in the first trimester interfered with cord serum inflammatory cytokine levels. The associations of maternal exposure to As, Cu and Cd with inflammatory cytokines showed sex differences. Further studies are warranted to support the findings and explore the mechanism of the susceptibility window and sex-specific disparity.

Accumulation, potential risk and source identification of toxic metal elements in soil: a case study of a coal-fired power plant in Western China

Coal-fired power plants (CPP) usually release massive numerous amounts of potentially toxic metal(loid)s (PTMs) into nearby ecosystems. There have been relatively few studies targeted on the ecological influences of PTMs related to the CPP in arid area. In this work, the distribution pattern, source apportionment and environmental risks of As, Cd, Cr, Hg, Pb and a couple of seldom monitored PTMs (Se, Zn, Co, Cu, Fe, Mn and Ni) in the soils near a coal electricity integration base were investigated in Hami, a city in northwestern China. Nemerow synthesis pollution index, geo-accumulation index and ecological risk index were used to assess pollution state of these PTMs in soils, and ordinary Kriging interpolation was used to analyze the spatial distribution for these elements. Methods of CA, PCA, CA and PAM were carried out for quantitative source analysis. The research outcome includes: (1) the contents of individual PTMs in most samples were greater than the background values, the pollution degrees of Se, Pb, Hg, Cd and As were significant, and some areas exceeded the warning threshold value; (2) the main sources of these PTMs were natural sources (35%), coal mine sewage (11%), atmospheric release during coal combustion (21%), dust generated from coal and combustion products (33%); (3) attention should be paid to the open-pit coal mines, shaft coal mines and ash dumps where the contents of metal elements were significantly polluted; and (4) wind is the main driving forces of PTMs migration in arid areas.

Human health risk assessment of air pollutants in the largest coal mining area in Brazil

The Candiota region, located in the extreme south of Brazil, has the largest mineral coal deposit in the country, and this activity is capable of releasing pollutants in which they are associated with the contamination of different matrices (soil, water, and air). The present study aimed to carry out a risk assessment to human health of atmospheric pollutants NO₂ and SO₂ and PM₁₀-bound metal(loid)s in the municipality of Candiota, in addition to evaluating the correlation of meteorological parameters for the dynamics and potential risk of these pollutants. Pollutants were sampled from stations located almost 4 km from coal exploration activities, and the trace elements As, Cd, Se, Pb, and Ni, in addition to NO₂ and SO₂, were evaluated. Risk assessment was conducted taking into account the risk to adults via the inhalation route. During the sampling period, all pollutants presented values lower than national legislation or internationally accepted values, and Pb was the element that presented the highest values throughout the sampled period. The risk assessment showed no carcinogenic and non-carcinogenic risks, even when considering the sum of the risk of all analyzed pollutants. It can be observed that the highest levels of Pb, As, and Se occurred in the winter season, while the levels of Ni and Cd were higher in the spring, and the meteorological parameters were correlated with the pollutants, even using a temporal lag of 5 days. Although the air pollutants evaluated did not present a risk to human health, continuous monitoring of regions with strong mineral exploration activity must be carried out with a view to maintaining the well-being of exposed populations, mainly because there are people living in areas closer to sources of coal pollution than distance to air quality monitoring stations.

Gestational and Neonatal Outcomes in Cities in the Largest Coal Mining Region in Brazil

Brazil has one of the largest mineral coal reserves in the world. More than 40% of this ore is in the Candiota Mine, in the extreme south of Brazil, which was previously identified as a hotspot of environmental pollution. In addition, an important part of Brazil's population suffers from socioeconomic vulnerability. Since there is no information on unfavorable gestational and neonatal outcomes associated with these problems, we conducted a cross-sectional study with 1950 mother-child binomials, aiming to evaluate the association between these outcomes and air pollution as well as socioeconomic, demographic and health variables in seven cities in the region. Of the total births, 11.6% were preterm and 9.5% of neonates had low birth weight (<2500 g). These conditions were also associated with skin color, previous abortions, birth type and prenatal care, as well as exposure to higher levels of coarse particulate matter (PM₁₀) during the first trimester of pregnancy. Regarding air pollutants, although the daily limits for PM₁₀ were exceeded on less than 5% of days, the annual average overtook the values proposed by WHO. Thus, we concluded that prematurity and low birth weight in this region are related to air pollution, and to socioeconomic variables and health care.