Concentrations Of Chemical Contaminants Research Articles

Assessment of the estuarine shoreline microplastics and mesoplastics of the River Itchen, Southampton (UK) for contaminants and for their interaction with invertebrate fauna

The presence of shoreline microplastics (1–5 mm) and mesoplastics (5–25 mm) in estuarine ecosystems is ubiquitous, but there remains little data on their composition, contamination status and ecological impacts. Chessel Bay Nature Reserve, situated in the internationally protected Itchen Estuary in Southampton, UK, has serious issues with shoreline plastic accumulation. In evaluating potentially adverse ecological impacts, the influence of quantities of shoreline microplastic (mp) and mesoplastic (MeP) material and adsorbed contaminants (PAHs and trace metals) on the biometrics and population dynamics of the burrowing supralittoral amphipod, Orchestia gammarellus, was assessed in this study. mp/MeP concentrations were variable in surface (0–42%: 0–422,640 mg/kg dry sediment) and subsurface horizons (0.001–10%: 11—97,797 mg/kg dry sediment). Secondary microplastics accounted for 77% of the total microplastic load (dominated by fragments and foams), but also comprised 23% nurdles/pellets (primary microplastics). Sorption mechanisms between contaminants and natural sediments were proposed to be the main contributor to the retention of PAHs and trace metal contaminants and less so, by mp/MeP. O. gammarellus populations showed a positive correlation with microplastic concentrations (Spearman correlation, R = 0.665, p = 0.036). Some reported toxicological thresholds were exceeded in sediments, but no impacts related to chemical contaminant concentrations were demonstrated. This study highlights a protected site with the severe plastic contamination, and the difficulty in demonstrating in situ ecotoxicological impacts.

Trace elements, dioxins and PCBs in different fish species and marine regions: Importance of the taxon and regional features

Chemical contaminant concentrations in wild organisms are used to assess environmental status under the European Marine Strategy Framework Directive. However, this approach is challenged by the complex intra- and inter-species variability, and the different regional features. In this study, concentrations in trace elements (As, Cd, Hg and Pb), polychlorinated biphenyls (PCBs), polychlorodibenzo-para-dioxines (PCDDs) and polychlorodibenzofuranes (PCDFs) were monitored in 8 fish species sampled on the continental shelf of three French regions: the Eastern English Channel (EEC) and Bay of Biscay (BoB) in the Northeast Atlantic Ocean, and the Gulf of Lions (GoL) in Western Mediterranean Sea. Our objectives were to identify species or regions more likely to be contaminated and to assess how to take this variability into account in environmental assessment. While concentrations were higher in benthic and demersal piscivores, PCB and PCDD/F concentrations (lipid-weight) were similar in most teleost species. For Cd, Hg and Pb, the trophic group accumulating the highest concentrations depended on the contaminant and region. Concentrations in Hg, PCBs and PCDD/Fs were higher in the EEC and/or GoL than in BoB. Cadmium and Pb concentrations were highest in the BoB. Lipid content accounted for 35%–84% of organic contaminant variability. Lipid normalisation was employed to enhance robustness in the identification of spatial patterns. Contaminant patterns in chondrichthyans clearly differed from that in teleosts. In addition, trophic levels accounted for ≤1% and ≤33% of the contaminant variability in teleost fishes in the EEC and BoB, respectively. Therefore, developing taxa-specific thresholds might be a more practical way forward for environmental assessment than normalisation to trophic levels.

The statistical power to detect regional temporal trends in riverine contaminants in the Chesapeake Bay Watershed, USA

Chemical contamination of riverine ecosystems is largely a result of urbanization, industrialization, and agricultural activities occurring on adjacent terrestrial landscapes. Land management activities (e.g., Best Management Practices) are an important tool used to reduce point and non-point sources of pollution. However, the ability to confidently make inferences about the efficacy of land management activities on reducing in-stream chemical concentrations is poorly understood. We estimated regional temporal trends and components of variation for commonly used herbicides (atrazine and metolachlor), total estrogenicity, and riverine sediment concentrations of total PCBs for rivers in the Chesapeake Bay Watershed, USA. We then used the estimated variance components to perform a power analysis and evaluated the statistical power to detect regional temporal trends under different monitoring scenarios. Scenarios included varying the magnitude of the annual contaminant decline, the number of sites sampled each year, the number of years sampled, and sampling frequency. Monitoring for short time periods (e.g., 5 years) was inadequate for detecting regional temporal trends, regardless of the number of sites sampled or the magnitude of the annual declines. Even when monitoring over a 20-year period, sampling a relatively large number of sites each year was required (e.g., >50 sites) to achieve adequate statistical power for smaller trend magnitudes (declines of 5–7%/year). Annual sampling frequency had little impact on power for any monitoring scenario. All sampling scenarios were underpowered for sediment total PCBs. Power was greatest for total estrogenicity, suggesting that this aggregate measure of estrogenic activity may be a useful indicator. This study provides information that can be used to help (1) guide the development of monitoring programs aimed at detecting regional declines in riverine chemical contaminant concentrations in response to land management actions, and (2) set expectations for the ability to detect changes over time.

Response of biomarkers to metals, hydrocarbons and organochlorine pesticides contamination in crabs (Callinectes ornatus and C. bocourti) from two tropical estuaries (São José and São Marcos bays) of the Maranhão State (northeastern Brazil)

Response of biomarkers to chemical contamination was evaluated in crabs of the Callinectes genus (Callinectes ornatus and C. bocourti) from two tropical estuaries (São José and São Marcos bays) of the Maranhão State (northeastern Brazil). Biomarkers evaluated included hepatopancreatic metallothionein-like proteins (MTLP) and lipid peroxidation (LPO), as well as muscle acetylcholinesterase (AChE). Tissue concentrations of metals (pereiopod muscle and hepatopancreas), hydrocarbons (hepatopancreas) and organochlorine pesticides (hepatopancreas) were also evaluated. Crab samples were collected in three sites of each estuary (São Marcos Bay and São José Bay). Sampling was performed in August/2012 (dry season), January/2013 (rainy season), August/2013 (dry season), and January/2014 (rainy season). Concentrations of chemical contaminants and responses of biomarkers showed significant spatial (São Marcos Bay and São José Bay) and/or seasonal (dry and rainy seasons) and annual (2012–2014) variability. However, a general higher Zn concentration was observed in hepatopancreas of crabs from São José Bay. In turn, a general higher Cd concentration paralleled by oxidative damage (LPO) was observed in hepatopancreas of crabs from São Marcos Bay. As expected, these findings support the idea that this bay is more intensively or chronically impacted by industrial activities while the São José Bay is likely more affected by domestic activities. Interestingly, LPO level in crab hepatopancreas showed to be the most reliable and adequate biomarker to distinguish the two bays.

Source- and polymer-specific size distributions of fine microplastics in surface water in an urban river

There is increasing concern about the environmental behaviors of microplastics (MPs), in particular fine MPs (FMPs), such as their concentrations, sources, size distributions, and fragmentation by weathering in waters. However, there is little information about size distributions of MP polymer types and their relationships to their sources. Here, we analyzed concentrations, compositions, and size distributions of 18 polymer types of MPs of >20 μm by micro-Fourier transform infrared spectroscopy with a novel pretreatment method in surface waters at five sites from the headwaters to the mouth of a Japanese river, and in influent and effluent from a sewage treatment plant (STP). The microplastic concentrations ranged from 300 to 1240 particles/m3 in surface waters. Cluster analysis identified two primary sources of MPs: residential wastewater at the headwater site and non-point sources from urban areas at downstream sites; concentrations of chemical contaminants from STPs were much higher at the downstream sites. The median particle sizes (D50) of MPs increased in urban areas at the downstream sites and were larger than those in influent and effluent. These results imply the release of larger MPs from non-point sources in urban areas. The size distributions of each polymer and all MPs could be fitted significantly to the Weibull distribution function. Values of D50, shape parameters, and scale parameters estimated from the functions were useful indicators for evaluating size distributions in detail. A significant positive correlation of D50 with the tensile strengths of virgin polymers among 13 dominant polymers detected in the surface water suggests that the fragmentation properties of each polymer are influenced by its physical strength. Multidimensional analysis with concentrations, polymeric compositions, and size distributions of MPs, including FMPs, could provide useful information about their sources and their environmental behaviors.

Evaluation of the Effect of Gold Mining on the Water Quality in Monterrey, Bolívar (Colombia)

Gold mining uses chemicals that are discharged into rivers without any control when there are no good mining practices, generating environmental and public health problems, especially for downstream inhabitants who use the water for consumption, as is the case in Monterrey township, where the Boque River water is consumed. In this study, we evaluate Boque River water quality analyzing some physicochemical parameters such as pH, heavy metals, Hg, and cyanide; bioassays (Lactuca sativa, Hydra attenuata, and Daphnia magna), mutagenicity (Ames test), and microbiological assays. The results show that some physicochemical parameters exceed permitted concentrations (Hg, Cd, and cyanide). D. magna showed sensitivity and L. sativa showed inhibition and excessive growth in the analyzed water. Mutagenic values were obtained for all of the sample stations. The presence of bacteria and somatic coliphages in the water show a health risk to inhabitants. In conclusion, the presence of Cd, Hg, and cyanide in the waters for domestic consumption was evidenced in concentrations that can affect the environment and the health of the Monterrey inhabitants. The mutagenic index indicates the possibility of mutations in the population that consumes this type of water. Bioassays stand out as an alert system when concentrations of chemical contaminants cannot be analytically detected.

Microbial quality of surface water and subsurface soil after wildfire

Runoff from wildfire affected areas typically carries high concentrations of fine burned residues or eroded sediment and deposits them in surface water bodies or on subsurface soils. Although the role of wildfire residues in increasing the concentration of chemical contaminants in both environments is known, whether and to what degree wildfire residues may affect microbial contaminants is poorly understood. To examine the effect of wildfire residues on growth and die-off of Escherichia coli (E. coli) —a pathogen indicator, we mixed stormwater with E. coli and suspended particles from the pre- and post-wildfire area in batch reactors and monitored E. coli concentration. E. coli grew initially in the presence of all particles, but the relative E. coli concentration was 10 times lower in the presence of wildfire residues than in natural soil from unaffected areas. Wildfire residues also decreased the persistence of E. coli during a 15-day incubation period. These results indicate that the growth or persistence of E. coli in surface water in the presence of wildfire residues was less than that in the presence of unburned soil particles, potentially due to depletion of nutrient concentration and/or loss of viability of bacteria in the presence of wildfire residues. To examine the transport potential of wildfire residues and their ability to facilitate the transport of E. coli in the subsurface system, suspensions containing wildfire residues and/or E. coli were injected through unsaturated sand columns—a model subsurface system. Transport of wildfire residues in sand columns increased with decreases in the depth and increases in the concentration of particles, but increased transport of wildfire residues did not result in the increased transport of E. coli, suggesting wildfire residues do not facilitate the transport of E. coli. Overall, the results indicate that wildfire residues may not increase the risk of the microbial contamination of surface water or groundwater via subsurface infiltration.

Influence of remediation on sediment toxicity within the Grand Calumet River, Indiana, USA

The Grand Calumet River (GCR), located in northern Indiana, is contaminated due to a wide range of historical industrial activities. This study was conducted to determine the influence of sediment remediation within the GCR on concentrations of chemical contaminants and toxicity to sediment-dwelling organisms. Between 2005 and 2016, sediments with high concentrations of metals and toxic organic compounds were remediated through a combination of removal, addition of activated carbon and organoclay amendments, and capping with sand or relatively uncontaminated sediment. Short-term and long-term sediment toxicity tests with the amphipod Hyalella azteca, the midge Chironomus dilutus, and the mussel Lampsilis siliquoidea were conducted with samples collected in 2013, 2015, and 2017, from 29 sites, including both remediated and non-remediated sites. Sediment chemistry and toxicity data for three groups of remediated sites (US Steel, West Branch, and East Branch) were compared to samples from contaminated but unremediated sites and to relatively uncontaminated reference sites. In general, remediated sediments had lower levels of PAHs, PCBs and metals, although sediments from the US Steel area still had elevated levels of PAH, PCB and chromium. Sediments from the three remediated sites and from reference sites showed significantly reduced toxic effects in short-term sediment bioassays, compared to unremediated sites. Variation in the long-term success of remediation may reflect site-specific factors such as the type of remediation and the potential for recontamination from uncontrolled sources.

Use of chemical concentration changes in coastal sediments to compute oil exposure dates

Oil spills can result in changes in chemical contaminant concentrations along coastlines. When concentrations are measured along the Gulf of Mexico over time, this information can be used to evaluate oil spill shoreline exposure dates. The objective of this research was to identify more accurate oil exposure dates based on oil spill chemical concentrations changes (CCC) within sediments in coastal zones after oil spills. The results could be used to help improve oil transport models and to improve estimates of oil landings within the nearshore. The CCC method was based on separating the target coastal zone into segments and then documenting the timing of large increases in concentration for specific oil spill chemicals (OSCs) within each segment. The dataset from the Deepwater Horizon (DWH) oil spill was used to illustrate the application of the method. Some differences in exposure dates were observed between the CCC method and between oil spill trajectories. Differences may have been caused by mixing at the freshwater and sea water interface, nearshore circulation features, and the possible influence of submerged oil that is unaccounted for by oil spill trajectories. Overall, this research highlights the benefit of using an integrated approach to confirm the timing of shoreline exposure.

Selection of biochemical and physiological parameters in the croaker Micropogonias furnieri as biomarkers of chemical contamination in estuaries using a generalized additive model (GAM)

Biochemical and physiological parameters in the croaker Micropogonias furnieri were evaluated as biomarkers of chemical contaminants in estuaries. Juvenile croakers (10–20 cm total body length) were collected in summer and winter (2011 and 2012), in two sites at the Lagoa dos Patos estuary (southern Brazil). Fish were also collected in summer (2011 and 2012) in one site at the Barra do Chui estuary (southern Brazil). Tissue (gills, muscle or liver) samples were dissected and analyzed for contaminants [metals, polycyclic aromatic hydrocarbons (PAHs) and organochlorine pesticides (OCPs)] and selected biochemical and physiological parameters [metallothionein-like proteins (MTLP), acetylcholinesterase (AChE) activity, ethoxyresorufin-O-deethylase (EROD) activity, and lipid peroxidation (LPO)]. Additionally, water samples were collected for water chemical analyses (salinity, pH, temperature, dissolved oxygen, total alkalinity, and sulfate concentration). Data obtained were integrated and analyzed, using Principal Component Analysis (PCA) and Generalized Additive Model (GAM) approaches. Results showed that changes in concentrations of chemical contaminants and responses of biochemical and physiological parameters did not show any pattern according to the site, season and year of fish collection. However, they were influenced by fish body length and water temperature and salinity. Liver LPO and EROD activity were not responsive to PAHs. However, liver LPO was responsive to HCB, p,p-DDD, p,p-DDT and endosulfan sulfate. In turn, gill MTLP concentration, muscle AChE activity and liver EROD activity were responsive to non-essential metals (Pb, Cd and Ag). Considering that the ecotoxicological modeling approach adopted (GAM) accounted for biological, spatial and temporal variability of data associated with fish body size and site, season and year of fish collection, gill MTLP concentration, muscle AChE activity, as well as liver LPO and EROD activity can be considered as reliable biomarkers of fish exposure to chemical contaminants in estuaries.

Field assessment of reproduction-related traits of chironomids using a newly developed emergence platform (E-Board)

Further progress in the development of reliable biomonitoring strategies requires to better link effects in aquatic ecological systems to ambient concentrations of chemical contaminants. Among existing tools, in situ bioassays using caging method represent an interesting way to achieve this challenge. However, elaboration of adapted exposure chambers and suitable operating procedures is still required, particularly to assess ecological relevant traits such as those related to the reproduction. In such context, we developed a new device (Emergence board – E-Board) which allows assessing in rivers the development of the Chironomus riparius species from the early fourth instar larvae to the adult stage. The system acts as a suspended matter trap floating in the subsurface of the water equipped of an emergence trap for catching adults. The system was tested in actual field conditions. Its easy handling allowed obtaining data which demonstrated its applicability for assessing the development of the chironomids. Moreover, by adapting energy-based models (DEB) specifically developed in the laboratory for the species C. riparius, we were able to predict the growth pattern and the emergence of chironomids in real environmental conditions. The E-Board represents thus a promising new in situ tool in perspective of evaluation of the quality of the ecosystems.

Incidence of Pediatric Inflammatory Bowel Disease in Finland: An Environmental Study.

The aim of this study was to explore possible environmental factors behind the regional differences in the incidence of pediatric inflammatory bowel disease (IBD). All of the patients diagnosed with IBD who were aged 0 to 14 years in Finland between 1987 and 2003 were identified from the Social Insurance Institution database. Finland was divided into squares of 250 × 250 m, and spatial variations of incidence rates were evaluated accordingly. The role of the environmental determinants (pediatric population density, agricultural industry, chemical contaminants of tap water and proximity to the sea or paper mills) in the geographic variations of the incidence rates was evaluated. During the study period, the overall incidence of pediatric IBD was 6.5 of 100,000 (95% confidence interval [CI] 6.1-6.9). The incidence in very sparsely populated areas (≤10 person-years per 250 × 250 m) was 9.2 of 100,000 (95% CI 6.3-13.1) and 5.6 of 100,000 (95% CI 4.8-6.4) in the districts with the highest population density (>800 person-years per 250 × 250 m). A nonsignificant trend toward the same direction was also seen for ulcerative colitis (trend P = 0.09). Chemical contaminant concentrations of tap water, residence near the seaside, or proximity to paper mills were not associated with the incidence of pediatric IBD. Our findings suggest higher incidence rates of pediatric IBD in the districts with low compared with high density of child population, but the differences cannot be explained by variations in the environmental exposures evaluated here.

Respiratory Protection for Firefighters— Evaluation of CBRN Canisters for Use During Overhaul

In the United States, there are approximately 366,600 structural fires each year. After visible flames are extinguished, firefighters begin the overhaul stage of firefighting to smother remaining hot spots and initiate investigations. Typically during overhaul significant ambient concentrations of chemical contaminants remain. However, previous research suggests that the use of air purifying respirators (APR) fitted with chemical, biological, radiological, and nuclear (CBRN) canisters may reduce occupational respiratory exposures. This pilot study used large-scale prescribed burns of representative structural materials to perform simultaneous, side-by-side, filtering and service-life evaluations of commercially available CBRN filters. Three types of CBRN canisters and one cartridge were challenged in repetitive post live-fire overhaul exposure tests using a sampling manifold apparatus. At a flow rate of 80L/min, nine tests were conducted in the breathing zone for three different exposure durations (0–15 min, 0–30 min, and 0–60 min). Fifty different chemicals were identified for evaluation and results indicate that 21 of the 50 chemicals tested were in the air of the overhaul environment. Respirable particles and formaldehyde were consistently present above the American Conference of Governmental Industrial Hygienists (ACGIH®) recommended exposure level (REL) and threshold limit ceiling value (TLVc), respectively. Each filter effectively reduced concentrations for respirable particulates below the maximum recommended level. Formaldehyde was reduced, but not consistently filtered below the TLVc. These results were consistent across all exposure durations. This study indicates that, regardless of brand, CBRN filters provide protection from the vast majority of particle and gas-phase contaminants. However, due to formaldehyde breakthrough, CBRN filters do not provide complete protection during firefighter overhaul.

Submerged appurtenances and pipelines: An assessment of water levels and contaminant occurrence

Submerged air vacuum valves and pipe leaks are potential entry points of contaminated water into drinking water distribution systems under low‐pressure conditions. Water levels in 20 valve vaults and 17 groundwater wells were monitored weekly for 8 months. The assembled data set indicated that water mains and air vacuum valves were commonly submerged in the investigated system. Urban runoff was found to be the dominant source of flooding in 11 of the 16 vaults containing water. A subset of 14 vaults and 10 piezometers were sampled for microbial and chemical parameters. Concentrations of chemical contaminants generally did not exceed drinking water standards. However, high counts of microbial fecal indicators were detected in numerous vaults. Runoff volumes of up to 255 L/mm of rainfall were found to enter a tested vault, and runoff water was identified as the main source of pesticides, personal care products, microbial fecal indicators, and hydrocarbons in vaults.

Silver European eels health in Mediterranean habitats

AbstractThe degradation in the quality of silver eel and their health could have been a major factor in the collapse of the European eel (Anguilla anguilla) population. However, the health status of the spawners has been poorly studied until now. This study evaluated the quality of migrant male silver eels from four Mediterranean habitats in France presenting different degrees of contamination: Canet‐Saint‐Nazaire, Salses‐Leucate and Bages‐Sigean lagoons and La Berre River. We considered pathogens including Anguillicoloides crassus and EVEX virus and the concentration of chemical contaminants including PCBs, OCs and heavy metals. Our study results revealed different patterns of pollution and infection in the four habitats, with high individual variability. No single silver eel was free of pollution. Total dichloro‐diphenyl‐trichloroethane (DDT) and copper contaminations, as well as the Swim bladder Degenerative Index (induced by parasitism), were remarkably high in eels from Canet lagoon, while eels from Salses lagoon showed lower levels of contaminants and parasite infection. A non‐negligible proportion of eels were strongly impacted with levels of contaminants/parasites that could potentially impair their migration and reproduction. Our study revealed low to moderate contamination levels compared with the other Mediterranean sites previously reported, except for high concentrations of DDTs and Cu in Canet lagoon. We discuss the contribution of these results in the context of possible implications for silver eels reproductive success and local eel population management.

Urban stormwater harvesting and reuse: a probe into the chemical, toxicology and microbiological contaminants in water quality

Stormwater is one of the last major untapped urban water resources that can be exploited as an alternative water source in Australia. The information in the current Australian Guidelines for Water Recycling relating to stormwater harvesting and reuse only emphasises on a limited number of stormwater quality parameters. In order to supply stormwater as a source for higher value end-uses, a more comprehensive assessment on the potential public health risks has to be undertaken. Owing to the stochastic variations in rainfall, catchment hydrology and also the types of non-point pollution sources that can provide contaminants relating to different anthropogenic activities and catchment land uses, the characterisation of public health risks in stormwater is complex, tedious and not always possible through the conventional detection and analytical methods. In this study, a holistic approach was undertaken to assess the potential public health risks in urban stormwater samples from a medium-density residential catchment. A combined chemical-toxicological assessment was used to characterise the potential health risks arising from chemical contaminants, while a combination of standard culture methods and quantitative polymerase chain reaction (qPCR) methods was used for detection and quantification of faecal indicator bacteria (FIB) and pathogens in urban stormwater. Results showed that the concentration of chemical contaminants and associated toxicity were relatively low when benchmarked against other alternative water sources such as recycled wastewater. However, the concentrations of heavy metals particularly cadmium and lead have exceeded the Australian guideline values, indicating potential public health risks. Also, high numbers of FIB were detected in urban stormwater samples obtained from wet weather events. In addition, qPCR detection of human-related pathogens suggested there are frequent sewage ingressions into the urban stormwater runoff during wet weather events. Further water quality monitoring study will be conducted at different contrasting urban catchments in order to undertake a more comprehensive public health risk assessment for urban stormwater.

The parameters of hygienic quality of four most common types of fish in Serbian market

The aim of this study was to show the comparative results of chemical and microbiological investigation of two freshwater fish species, pangasius, which, in recent years, occupies a leading position on the market, and carp, as the most common fish in the national aquaculture and two species of marine fish, hake and mackerel. Microbiological testing included Salmonella species, coagulase-positive staphylococci, sulphite-reducing clostridia, E. coli and total aerobic mesophilic bacteria. Of chemical contaminants, the presence of the following organochlorine pesticides (OClP) was investigated: gamma-hexachlorocyclohexane (gamma- HCH), i.e. lindane, alpha-HCH, beta-HCH, aldrin, dieldrin, heptachlor, cis-and trans-heptachlor epoxide, p, p'-DDT (dichloro diphenyl trichloroethane), pp'-DDE (dichlorodiphenyl dichloroethane), pp'-DDD dichlorodiphenyl dichloroethane), endrin, hexachlorobenzene (HCB), alpha-and gamma-chlordane. In the same samples congeners of polychlorinated biphenyls (PCBs), IUPAK no. 28, 52, 101, 118, 138, 153, 180, were determined as well and the heavy metals lead, cadmium and mercury. The presence of coagulase-positive staphylococci, sulphite reducing clostridia, Salmonella spp. and E. coli was not established in the tested samples. The total count of aerobic bacteria was the highest in carp samples (3.40 } 0.57), but did not exceed the recommended limit of acceptability of 5.69 log cfu/g. Amounts of dieldrin, HCH, HCB and chlordane were lower than the detection limit (0.001 mg/kg) in samples of all four fish species. For pangasius samples, the total amount of DDT ranged from detection limit (0.001 mg/kg) to 0,005 mg/kg, while the values of pesticides in samples of mackerel were in the range of the detection limit (0.001 mg kg) to 0.019 mg/kg. The sum of heptachlor quantities and heptachlorepoxide in samples of pangasius ranged from the detection limit to 0.009 mg/kg, and in samples of carp from the detection limit to 0.019 mg/kg. In samples of pangasius, mackerel and hake the content of lindane was below the detection limit (0.001 mg/kg), while in the carp samples ranged from the detection limit to 0.017 mg/kg. The content of polychlorinated biphenyls ranged from the detection limit (0.001 mg/kg) to 0.030 mg/ kg, for the samples of pangasius and to 0.089 mg/kg for carp samples. In samples of mackerel, sum of aldrin and dieldrin ranged from the detection limit to 0.010 mg/kg, while in samples of pangasius, carp and hake its value was below the detection limit (0.001 mg / kg). Amounts of heavy metals (Hg, Pb and Cd) were also below the maximum residue limits (MRL). Lead content was the highest in pangasius samples, 0.21 mg/kg, while the highest content of cadmium, 0.049 mg/kg, was detected in samples of hake. Samples of mackerel had the highest mercury content, which amounted to 0.162 mg / kg. In respect to food safety, samples of fish were of good quality, with the concentration of chemical contaminants below the maximum residue limits and with no increase in the number of microorganisms.

Ecological Assessment of a Marine Coastal Area Affected by a Power Plant Water Discharge (Brindisi, Adriatic Sea)

Coastal ecosystems are subjected to multiple stresses, from physical disturbance to chemical contamination related to the local anthropogenic activities. The recent European directives and Italian laws recommend that the assessment of the ecological quality of costal seawater should be based on an integrated approach, taking into account the ecological complexity of the systems and highlighting the potential sources of impact. Here, we present the results of an environmental study carried out in the marine coastal area affected by the sea discharge of a Combined Cycle Power Plant (Torre Cavallo, Brindisi) and characterized by the presence of a Posidonia oceanica meadow. The study focused on the concentration of chemical contaminants in sediments, coupled with the study of quali-quantitative determinations of biological benthic communities meio- and macrozoobenthos). Data were integrated with data of phenology and lepidochronology of P. oceanica, as well as the concentrations of trace elements in leaves and rhizomes, in order to identify potential sources of stress. Results suggested a good status of health of the coastal marine ecosystem.

Effects of cumulative stress on fish health near freshwater outlet sluices into the sea: A case study (1988–2005) with evidence for a contributing role of chemical contaminants

Epizootic skin diseases in euryhaline flounder (Platichthys flesus) in the Dutch Wadden Sea were first reported in 1988. Particularly high prevalences of skin ulcers (up to one-third of individual fish being affected) were encountered in the vicinity of sluices draining freshwater from IJsselmeer Lake, in contrast with much lower levels in the freshwater bodies behind the sluices and open sea areas (<2%). It was proposed that salinity stress, high bacterial loads, nutritional deficiencies, and obstruction to fish migration by the sluices could all be involved in disease causation. Results of follow-up surveys at these outlet sluices from 1994 to 2005 further substantiate our preliminary findings. The follow-up data also show a general reduction in disease and improved condition factor during this period, which can be explained by improved habitat conditions for the flounder, partly due to effective sluice gate management. Furthermore, statistical correlations (p<0.05) were demonstrated between flounder ulcer occurrence and chemical contaminant concentrations in liver (Hg, Cd, Cu, Zn) and bile (the metabolite 1-OH pyrene as an indicator of chronic polycyclic aromatic hydrocarbon exposure), and histological liver lesions generally indicative of contaminant exposure (hydropic vacuolization of biliary duct epithelial cells). The findings suggest that a combination of osmotic and contaminant-induced stress also contributed to the observed disease patterns.

Water Distribution System Modeling and Simulation

This paper describes a project to integrate EPANET, Giris and SCADA to assist water engineers in assessing the water distribution system in city S. The integrated system simulates the flow and concentration of chemical contaminants in municipality's water distribution system. The integrated model is a powerful tool for routine planning and emergency response. The capabilities of the model can greatly assist in the decision making processes for network asset inventory, rehabilitation requirements, and financial planning. The system was tested using the S City database composed of approximately 13219 junctions and 14832 pipes whose diameter not less than 300 mm.