Multi-compartmental environmental surveillance of a petrochemical area: levels of micropollutants

Since 2002, the chemical/petrochemical industrial zone of Tarragona County (Catalonia, Spain) is being annually monitored. As part of the environmental surveillance program, in this study the levels of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), polychlorinated naphthalenes (PCNs), polycyclic aromatic hydrocarbons (PAHs), and metals (As, Cd, Cr, Hg, Mn, Pb and V) were determined in soil and vegetation samples collected in 4 areas of Tarragona County (chemical, petrochemical, urban/residential, and unpolluted). Moreover, the airborne concentrations of the same micropollutants were determined in each area. In soil samples, significant higher levels of PCNs and higher concentrations of PCDD/Fs and PAHs were found in the urban zone. PCDD/F levels in vegetation samples significantly decreased from 2002. The concentrations of Cr in soil samples, as well as V levels in vegetation samples collected in the vicinity of an oil refinery were significantly higher than those found in the unpolluted zones. A significant and progressive increase in V concentrations was also noted. The current results clearly indicate that the petrochemical industry is still being an important focus of inorganic pollution for the surrounding environment. In air, the higher amount of the 7 carcinogenic PAHs suggests a relatively greater impact on the petrochemical and urban areas. The temporal trend of the global pollution was also studied an Integral Risk Index was applied.     

Survival and activity of Streptococcus faecalis and Escherichia coli in petroleum-contaminated tropical marine waters

The in situ survival and activity of Streptococcus faecalis and Escherichia coli were studied using membrane diffusion chambers in tropical marine waters receiving oil refinery effluents. Protein synthesis, DNA synthesis, respiration or fermentation, INT reduced per cell, and ATP per cell were used to measure physiological activity. Cell densities decreased significantly over time at both sites for both S. faecalis and E. coli; however, no significant differences in survival pattern were observed between S. faecalis and E. coli. Differences in protein synthesis between the two were only observed at a study site which was not heavily oiled. E. coli was more active in protein synthesis and respiration than S. faecalis at both oiled and unoiled sites, and the percentage of the E. coli population that was respiring was significantly higher than S. faecalis fermenting cells at both sites. However, S. faecalis cells were more active in DNA synthesis and higher in ATP content than E. coli cells at both sites. Although fecal streptococci have been suggested as a better indicator of fecal contamination than fecal coliforms in marine waters, in this study both E. coli and S. faecalis survived and remained physiologically active for extended periods of time. These results suggest that the fecal streptococci group is not a better indicator of fecal contamination in tropical marine waters than the fecal coliform group, especially when that environment is high in long-chained hydrocarbons.     

Health risks of environmental exposure to metals and herbicides in the Pardo River,Brazil

Mixture of metals and herbicides in rivers may pose relevant risks for the health of surrounding communities. Humans may be exposed to river pollution through intake of contaminated water and fish, as well as irrigated agricultural products. The aim of this study was to assess the human health risks of environmental exposure to metals and herbicides through water and fish intake in the Pardo River. Metals (Al, As, Be, Cd, Cr, Cu, Pb, Mn, Hg, Ni, Tl, Sn, V, and Zn) were analyzed in river water and in edible fish. Herbicides (ametryn, atrazine, diuron, hexazinone, simazine, and tebuthiuron) were analyzed in river water. Seasonal variances were also studied. Aluminum, Cd, Cu, Mn, Pb, and Zn levels in river water were higher than the USEPA benchmarks. Non-carcinogenic risks due to pollutants mixture exposure were above the limit, and carcinogenic risks of As exposure were >10^?6 in the sampling points during the rainy season. Metal levels in fish were lower than the Brazilian legislation and do not pose a threat to public health. Herbicides were detected in four sampling points, with atrazine concentrations (range 0.16–0.32 μg/L) below the Brazilian standard (2.0 μg/L), but above the European Union standard (0.1 μg/L). Considering the water supply needs of cities located in the Pardo River Basin and the persistence of metals and herbicides, the present study indicated that there was a seasonal influence on non-carcinogenic and carcinogenic risks to human health, especially in the rainy season. Studies for water treatment plants implantation should consider the risks of exposure to persistent substances, in order to protect the population.     

Proteomic analysis of chromate-induced modifications in Pseudokirchneriella subcapitata

In this work, we have analyzed the changes in the protein expression profile elicited by chromium (Cr) exposure in the freshwater green alga Pseudokirchneriella subcapitata, a well known bio-indicator of water pollution. We tested two experimental conditions, namely 0.2 and 1 ppm of potassium dichromate; this concentration range includes the environmentally-relevant concentrations. Results show that neither concentration of potassium dichromate tested inhibited algal growth. However, the proteomic approach allowed the identification of relevant modifications in protein expression. In fact, among 800 protein spots detected by two-dimensional electrophoresis, 16 Cr-regulated proteins, including predicted and novel ones, were identified using tandem mass spectromic protein analysis.The results demonstrate a Cr-specific action in altering several photosynthetic proteins, such as ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO), RuBisCO activase, Light Harvesting Chla/b protein complex, and stress related Chla/b binding protein1. Although Cr toxicity with respect to photosynthesis has been already documented, here we have identified, for the first time, the target proteins of this toxicity. Cr also induced a modulation of some proteins involved in the metabolism of the amino acids glutamine, arginine and methionine. These data are supported by changes in cellular polyamine (PA) accumulation. Present findings provide new insight into the molecular mechanisms underlying Cr toxicity in P. subcapitata.     

Dioxin and dibenzofuran concentrations in adipose tissue of a general population from Tarragona, Spain

Polychlorinated dibenzo-p-dioxin (PCDD) and polychlorinated dibenzofuran (PCDF) levels were determined in adipose tissue of 15 autopsied subjects who at the time of death had lived in the city of Tarragona (Catalonia, Spain) and surroundings during at least the last 10 years. PCDD/F concentrations ranged between 13.37 and 69.37 ng I-TEQ/kg fat, with mean and median values of 30.98 and 26.30 ng I-TEQ/kg fat, respectively. PCDD/F concentrations were higher (p < 0.01) in women (mean value: 44.95 ng I-TEQ/kg fat) than in men (mean value: 24.00 ng I-TEQ/kg fat). Although individuals living in industrial areas showed higher PCDD/F levels than those living Tarragona downtown the difference was not statistically significant. When Principal Component Analysis was applied to the concentrations of PCDD/Fs found in the 15 adipose tissue samples together with those found in 20 blood samples collected in a previous study, a single two-dimensional model was obtained, which would explain 62.9% of the variance in the data. The PCDD/F concentrations in adipose tissue found in the current study are of the same order of magnitude than those reported for most industrialized countries.     

A fuzzy expert system for soil characterization

As soil is a natural resource not always renewable, the risk characterization of contaminated soils is an issue of great interest. Artificial Intelligence (AI), based on Decision Support Systems (DSSs), has been developed for a wide range of applications in contaminated soil management. Decision trees have already shown to be easy to interpret and able to treat large scale applications. Fuzzy logic gives an improvement in the perturbations and the variance of the training data, due to the elasticity of fuzzy set formalism. In this study, we have developed a classificatory tool applied to characterize contaminated soil in function of human and environmental risks. Knowledge engineering for constructing the Soil Risk Characterization Decision Support System (SRC-DSS) involves three stages: knowledge acquisition, conceptual design and system implementation. A total of 26 parameters were divided into three groups to facilitate the configuration of the expert system: source attributes, transfer vector attributes, and local properties. Sixteen case studies were evaluated with the SRC-DSS. In comparison with other techniques, the results of the current study have shown that SRC-DDS is an excellent tool to classify and characterize soils according to the associated risk.