César A. Ilizaliturri-Hernández

Exposure to persistent organic pollutants (POPs) and DNA damage as an indicator of environmental stress in fish of different feeding habits of Coatzacoalcos, Veracruz, Mexico

The region of Coatzacoalcos, Veracruz hosts one of the largest and most important industrial areas of Mexico and Latin America. Industrial development and rapid population growth, have triggered a severe impact on aquatic ecosystems of the region. The aim of this study was to determine the levels of POPs in sediment and in muscle tissue of five fish species from different trophic levels in downstream residents of the Coatzacoalcos River, and their integration with DNA damage in the fish, evaluated with the comet assay in whole blood as a biological indicator of stress, in order to obtain a baseline of the ecological condition of the region. The compounds detected in sediment and in muscle tissue were hexachlorobenzene (HCB), α-, β-, γ-hexachlorocyclohexane (HCH), dichlorodiphenyltrichloroethane (DDT), dichlorodiphenyldichloroethylene (DDE), mirex and polychlorinated biphenyls (PCBs). Sediment concentrations of these pollutants (except for mirex) exceeded the values of protection provided by international guidelines, suggesting a potential risk to aquatic life in the region. DNA damage recorded in the fish species is evidence of exposure to a mix of genotoxic pollutants, which combined with exposure to POPs, reflects the degree of environmental stress of aquatic organisms in the region. The results of this study show the importance of determining the presence of contaminants in the environment, the bioaccumulation in tissues and their effects on exposed organisms, providing an integrated approach in assessing the health of aquatic ecosystems.

Using urinary 1-hydroxypyrene concentrations to evaluate polycyclic aromatic hydrocarbon exposure in women using biomass combustion as main energy source

Abstract Context: The use of solid fuels for cooking and heating is likely to be the largest source of indoor air pollution on a global scale. Objective: The aim of this study was to investigate the urinary excretion of 1-hydroxypyrene (1-OHP) in women living in a rural community, where biomass combustion is used as main energy source during a working day. Materials and methods: The study was performed on urine samples collected in 2012, of 30 healthy women who were residents of a rural community in San Luis Potosi, Mexico. Urine was collected from each woman at three time points (morning, post-lunch and evening) during a working day. The analysis of urinary 1-OHP was performed using high-performance liquid chromatography (HPLC). Also, a health-risk assessment was conducted. Results: The highest levels of 1-OHP in this study were found in the samples taken in the evening (geometric mean ± SD; 0.36 ± 0.13 µg/g creatinine). However, no significant differences among 1-OHP concentrations in the evening and post-lunch samples (0.27 ± 0.10 µg/g creatinine; 0.58 ± 0.67 µg/L) were observed. But, the 1-OHP levels (0.17 ± 0.13 µg/g creatinine; 0.19 ± 0.21 µg/L) found in samples collected in the morning were significantly lower than the 1-OHP levels found in samples collected during post-lunch and evening time. Discussion and conclusion: The data shown in this study demonstrated an increment in the exposure levels to PAHs in women across the shift. However, no health risk was found in this study.

Exposición infantil al plomo en sitios contaminados

OBJETIVO: Determinar el grado de la exposicion infantil al plomo en diversos tipos de sitios contaminados. MATERIAL Y METODOS: El estudio se realizo de junio 2008 a diciembre 2009 en cuatro sitios de Mexico: metalurgica de Avalos, Chihuahua.; metalurgica de Morales, San Luis Potosi (SLP); zona alfarera en La Trinidad, Tlaxcala, y sitio minero en Cedral, SLP. Se cuantifico plomo en polvo y se realizo un biomonitoreo humano en ninos de la comunidad. RESULTADOS: Los valores obtenidos de plomo en polvo exterior superaron el limite establecido de 400 mg/kg para suelos residenciales en un intervalo de valores para los cuatro sitios de 62 a 5 187 mg/kg. En cuanto al monitoreo biologico, todas las poblaciones presentaron valores extremos, desde los 22 µg/dL en Cedral, 31 µg/dL en Morales, y 32 µg/dL en Avalos, hasta los 52 µg/dL en La Trinidad. Es importante senalar que encontramos una correlacion positiva y significativa entre los valores de plomo en polvo y plomo en sangre en todos los sitios de estudio (p<0.001). CONCLUSION: Estos sitios son un ejemplo de los riesgos en salud relacionados con la exposicion a plomo en Mexico; por consiguiente, se requiere de un programa nacional de salud publica dirigido a reducir la exposicion a este metal en poblaciones vulnerables.

Rapid analysis of persistent organic pollutants by solid phase microextraction in serum samples.

A simple and rapid headspace solid-phase microextraction (HS SPME) based method is presented for the determination of Persistent Organic Pollutants (POPs) in human serum by gas chromatography (GC) coupled to mass detector (MS) with electron impact ionization (EI). As an outcome of the assessment of several polymer phases; the one with the best result was the PDMS fiber (100 μm). A multivariate analysis of variance by permutations (PERMANOVA) was performed to establish the optimal extraction conditions as a function of temperature and time variables. The results were 1 mL serum+200 µL H2SO4 9M+1 mL of deionized water at 600 rpm with a temperature of 80°C for 50 min to expose the fiber. The limits of detection (LOD) for POPs pesticides fell within the 0.22-5.41 ng/mL interval, and within 0.07-1.79 ng/mL for PCBs; a linear method was used with correlation coefficients (r) higher than 0.99. Recovery percentages at low concentrations (15 ng/mL) were 67.8-120.2%, and at high concentrations (75 ng/mL) 80.2-119.2%. Evaluated precision as percentage Relative Standard Deviation (RSD%) of repeatability and reproducibility was within a range of 0.5-9% and 0.3-21%, respectively. This analytical method prevents some of the main problems for quantifying POPs in human serum, such as the elimination of the solvents, sample handling, integration of extraction steps, pre-concentration and introduction of samples; consequently, the time and cost of analyzing the sample can be significantly reduced. The method developed was applied to determine exposure to POPs in samples of children living in different polluted sites in Mexico. In children living in indigenous communities results show exposure to DDE (median 29.2 ng/mL range 17.4-52.2 ng/mL) and HCB (median 2.53 ng/mL range 2.50-2.64 ng/mL); whereas in the industrial scenario, exposure to HCB (median 2.81 ng/mL range 2.61-3.4 ng/mL) and PCBs (median Σ-PCBs 22.2 ng/ml range 8.2-74.6 ng/mL) and finally in petrochemical scenario was demonstrated exposure to HCB (median 2.81 ng/mL range 2.61-3.4 ng/mL) and PCBs (Σ-PCBs median 7.9 ng/mL range 5.4-114.5 ng/mL).

Effect of Mining Activities in Biotic Communities of Villa de la Paz, San Luis Potosi, Mexico

Mining is one of the most important industrial activities worldwide. During its different stages numerous impacts are generated to the environment. The activities in the region have generated a great amount of mining residues, which have caused severe pollution and health effects in both human population and biotic components. The aim of this paper was to assess the impact of mining activities on biotic communities within the district of Villa de la Paz. The results showed that the concentrations of As and Pb in soil were higher than the national regulations for urban or agricultural areas. The bioavailability of these metals was certified by the presence of them in the roots of species of plants and in kidneys and livers of wild rodents. In regard to the community analysis, the sites that were located close to the mining district of Villa de la Paz registered a lower biological diversity, in both plants and wild rodents, aside from showing a change in the species composition of plant communities. The results of this study are evidence of the impact of mining on biotic communities, and the need to take into account the wildlife in the assessment of contaminated sites.

Plasma asymmetric dimethylarginine (ADMA) levels in Mexican women exposed to polycyclic aromatic hydrocarbons (PAHs): A preliminary study

Recent studies indicate that exposure to environmental pollutants (as polycyclic aromatic hydrocarbons) is a very important risk factor for development of cardiovascular diseases (CVDs). Correspondingly, in recent times asymmetric dimethylarginine (ADMA) has been proposed as a new and meaningful biomarker predictor for the risk of CVDs. Therefore, the objective of this study was to evaluate plasma ADMA concentrations in Mexican women (n=155) exposed to polycyclic aromatic hydrocarbons (PAHs). Urinary 1-hydroxypyrene [(1-OHP), exposure biomarker for PAHs] levels were quantified using a high performance liquid chromatography (HPLC) technique and plasma ADMA concentrations were analyzed using a commercially available ELISA kit. Urinary 1-OHP levels in all women assessed ranged from <LOD to 8.80μmol/mol creatinine. Regarding plasma ADMA concentrations, the mean levels ranged from 0.66 to 1.00μmol/L. Moreover, a significantly relationship was found between plasma ADMA concentrations and urinary 1-OHP levels (p=0.005; r=0.390). In conclusion, the results showed in this study demonstrated that the urinary 1-OHP levels were significant predictors of plasma ADMA concentrations in Mexican women exposed to PAHs. Although with due caution regarding the low representativeness of the present screening, it can be considered as a preliminary work to perform prospective studies including greater number of individuals and focusing in a more complete characterization of the effects produced by PAHs exposure on cardiovascular health.

Human health risks associated with heavy metals in soil in different areas of San Luis Potosí, México

ABSTRACT The aim of this study was to develop a health risk assessment in different areas of San Luis Potosí, México. Four heavy metals (arsenic, mercury, cadmium, and lead) were analyzed in soil from communities assessed. The mean arsenic concentration was significantly higher (p < .05) in the city of San Luis Potosí (51.85 mg/kg) compared to the other assessed areas (5.52–8.43 mg/kg). For cadmium, the mean concentration was significantly higher (p < .05) in Santa Maria Picula (7.46 mg/kg) than in the other areas (3.72–4.15 mg/kg). Regarding mercury levels, a significantly higher (p < .05) mean concentration was found in Mezquitic (1.54 mg/kg) compared to other areas (0.56–0.81 mg/kg). Lastly, when comparing the mean lead concentration in the city of San Luis Potosí (108 mg/kg), it was found to be significantly lower (p < .05) than in other areas (219–227 mg/kg). Subsequently, a probabilistic health risk assessment was performed, ingestion was the major exposure pathway for all four metals. Maximum cumulative hazard index (HI) values showed higher risk in all sampled locations (HIs > 1.0), suggesting that these sites can pose a non-carcinogenic risk to the populations (children) living in those areas. This study highlights the necessity of establishing a biomonitoring program for the surveillance of the child populations living in the assessed locations.

Assessment of the polychlorinated biphenyls (PCBs) levels in soil samples near an electric capacitor manufacturing industry in Morelos, Mexico

In Mexico, polychlorinated biphenyls (PCBs) were principally used as heat transfer chemicals in electric transformers and capacitors as well as hydraulic fluids and lubricants in heavy electrical equipment since the early 1940s. However, although PCBs have been banned in Mexico, their past and present improper disposal has resulted in environmental contamination. Therefore, the aim of this study was to evaluate the PCBs levels in soil samples in the immediate area of an electric capacitor manufacturing industry, which was established several years ago in Alpuyeca, Morelos, Mexico. To confirm the presence of PCBs, surface soil samples (1–5 cm in depth) were collected from the vicinity of the industry. We determined the concentrations of 40 PCB congeners in soil samples using gas chromatography/mass spectrometry. The total PCBs levels in the soil samples ranged from 6.2 to 108460.6 μg kg−1. Moreover, when we analyzed the results of the congeners (non-dioxin-like PCBs and dioxin-like PCBs), the levels of non-dioxin-like PCB congeners ranged from 5.7 to 103469 μg kg−1 and the levels of dioxin-like PCB congeners ranged from 0.5 to 4992 μg kg−1. Considering that soil is an important pathway of exposure in humans, analysis of PCBs levels in blood (as a biomarker of exposure) is necessary in individuals living in Alpuyeca, Morelos.

Linking fish consumption patterns and health risk assessment of mercury exposure in a coastal community of NW Mexico

ABSTRACT We aimed at characterizing the methylmercury (MeHg) exposure through fish consumption in two populations (common general and fishing-related population (FRP)) using a probabilistic health risk assessment in children, women of childbearing age, and adults in Mazatlán. The hazard quotients (HQs) were obtained from fish consumption, defined through a survey, and the levels of mercury in fishery products, obtained from published information. The average fish ingestion rate (IRfood) was higher in the FRP (167.85 g d−1) than in the general population (GP) (140.9 g d−1). However, HQs were significantly (p < 0.05) higher in the GP (ranging from 0.18 to 10.91) compared to the FRP (0.20 to 2.48); significant differences were also found among groups of both populations. Remarkably, children in both populations exhibited the highest proportions of risk, reaching up to 97% in GP. For all populations, fish consumption was the most important variable influencing MeHg exposure. Overall, for MeHg exposure, there is no safe level of fish consumption without risk, and actions should be taken to mitigate possible risk; further research with current data is needed to assess potential health risks associated with MeHg exposure, particularly in children.

Exposure Assessment to Persistent Organic Pollutants in Wildlife: The Case Study of Coatzacoalcos, Veracruz, Mexico

Until the early 70s, it was thought that pollution was a phenomenon circumscribed to zones where pollutants were generated. Because of that, in each country concern was limited to regions where pollutant concentration was higher or its danger was greater. However, it has gradually become aware that pollution is a problem that affects everybody and, because of that, everybody is responsible to control it, regardless of the sites distance where pollutants are produced. Therefore, the problem of pollution has become a global phenomenon. Mankind has always depended on natural resources located in the region where they dwell. Nevertheless, the fast population growth coupled with a fast agricultural and industrial development as well as life style changes have increased emissions of pollutants in different ecosystems. Persistent organic pollutants (POPs) is a group of compounds chemically very stable, able to travel considerable distances and it is resistant to natural degradation processes, most of them were produced to be used as pesticides and certain chemicals to be used as industrial processes, and others are generated as by-products unintentionally from human activities, such as combustion processes or power generation (PNUMA, 2005). Most of these compounds are highly toxic; they bioaccumulate in human and animal tissue, mainly in the fatty tissues, and can damage different organs and systemic targets such as the liver, kidney, hormonal system, nervous system, etc., of both humans and wildlife. According to the Stockholm Convention held in 2001, there are twelve compounds known as POPs: pesticides (DDT, aldrin, chlordane, dieldrin, endrin, mirex, toxaphene and heptachlor), industrial chemicals (hexachlorobenzene and polychlorinated biphenyls -PCB-) and unintentional compounds (dioxins, furans, PCDD-and PCDF-) [Albert, 2004]. In May of 2009 nine new Chemicals were added to the POPs list: alpha hexachlorocyclohexane, beta hexachlorocyclohexane; hexabromodiphenyl heptabromodiphenyl ether and ether tetrabromodiphenyl pentabromodiphenyl ether and ether chlordecone, hexabromobiphenyl, lindane, pentachlorobenzene, perfluorooctane sulfonic acid, its salts and perfluorooctane sulfonyl fluoride.