Contamination Hotspots Research Articles

Comprehensive target analysis and TOP assay of per- and polyfluoroalkyl substances (PFAS) in wild boar livers indicate contamination hot-spots in the environment

The suitability of wild boar liver as a bioindicator of per- and polyfluoroalkyl substances (PFAS) in the terrestrial environment was investigated. Samples from 50 animals in three different areas associated with (1) contaminated paper sludges distributed on arable land (PS), (2) industrial emissions of PFAS (IE) and (3) background contamination (BC) were analyzed for 66 PFAS, including legacy PFAS, novel substitutes and precursors of perfluoroalkyl acids (PFAAs). Additionally, the Total Oxidizable Precursor (TOP) assay was performed to determine the formation potential of PFAAs from precursors. In total, 31 PFAS were detected with site-specific contamination profiles. PFAS concentrations in livers from area PS and IE (567 and 944 μg kg−1 wet weight, respectively) were multiple times higher than from area BC (120 μg kg−1). The dominating PFAS were the legacy compounds perfluorooctane sulfonic acid (PFOS) in areas PS and BC (426 and 82 μg kg−1, respectively) and perfluorooctanoic acid (PFOA) in area IE (650 μg kg−1). In area IE, the compounds 4,8-dioxa-3H-perfluorononanoic acid (DONA) and hexafluoropropylene oxide dimer acid (HFPO-DA) – which are used as substitutes for PFOA – were determined at 15 and 0.29 μg kg−1, respectively. The formation potential of PFAAs was highest in area PS, but generally lower than the contamination with PFAAs. The pattern of perfluoroalkyl carboxylic acids (PFCAs) in wild boar liver reflects the contamination of the local soil at the two hot-spot areas IE and PS. This first comparison of PFAS contamination between wild boars and soil suggests that wild boar livers are suitable bioindicators for PFAS contamination in the terrestrial environment. Moreover, in terrestrial samples from area IE, legacy PFAS were found to be retained for a longer period as compared to riverine samples (suspended particulate matter and chub filet).

A methodology for using Lambda phages as a proxy for pathogen transmission in hospitals

One major concern in hospitalized patients is acquiring infections from pathogens borne on surfaces, patients, and healthcare workers (HCWs). Fundamental to controlling healthcare-associated infections is identifying the sources of pathogens, monitoring the processes responsible for their transmission, and evaluating the efficacy of the procedures employed for restricting their transmission. To present a method using the bacteriophage Lambda (λ) to achieve these ends. Defined densities of multiple genetically marked λ phages were inoculated at known hotspots for contamination on high-fidelity mannequins. HCWs then entered a pre-sanitized simulated hospital room and performed a series of patient care tasks on the mannequins. Sampling occurred on the scrubs and hands of the HCWs, as well as previously defined high-touch surfaces in hospital rooms. Following sampling, the rooms were decontaminated using procedures demonstrated to be effective. Following the conclusion of the simulation, the samples were tested for the presence, identity, and densities of these λ phages. The data generated enabled the determination of the sources and magnitude of contamination caused by the breakdown of established infection prevention practices by HCWs. This technique enabled the standardized tracking of multiple contaminants during a single episode of patient care. Unlike other biological surrogates, λ phages are susceptible to common hospital disinfectants, and allow for a more accurate evaluation of pathogen transmission. Whereas our application of these methods focused on healthcare-associated infections and the role of HCW behaviours in their spread, these methods could be employed for identifying the sources and sites of microbial contamination in other settings.

A Hotspot of TTX Contamination in the Adriatic Sea: Study on the Origin and Causative Factors.

Tetrodotoxins (TTXs), the pufferfish venom traditionally associated with Indo-Pacific area, has been reported during last decades in ever wider range of marine organisms and ever more geographical areas, including shellfish in Europe. Wild mussels (Mytilus galloprovincialis) grown in the Marche Region (N Adriatic Sea, Italy) were shown to be prone to TTX contamination during the warm season, with a suspected role of Vibrio alginolyticus characterized by non-ribosomal peptide synthetase (NRPS) and polyketide synthase (PKS)-encoding genes. This work aimed to deepen the knowledge about the toxin's origin and the way through which it accumulates in mussels. A two-year study (spring-summer 2020-2021) confirmed the recurrent presence of TTX (11-68 µg kg-1) in the official monitored natural mussel beds of the Conero Riviera. During 2021, a supplementary nonroutine monitoring of a natural mussel bed in the same area was carried out weekly from June until August for TTXs and/or the presence of V. alginolyticus. Biotic (mussels, mesozooplankton, worms and phytoplankton); abiotic (water and sediment) matrices and phytoplankton assemblage characterizations were studied. Mussels showed relevant TTX contamination levels (9-296 µg kg-1) with extremely rapid TTX accumulation/depletion rates. The toxin presence in phytoplankton and its distribution in the different mussel tissues supports its possible exogenous origin. The V. alginolyticus count trend overlaps that of TTX contamination in mussels, and similar trends were reported also for some phytoplankton species. The role of V. alginolyticus carrying NRPS or PKS genes as a possible TTX source and of phytoplankton as a "potential vector" should therefore be further investigated.

Quantitative relationships of perfluoroalkyl acids in drinking water associated with serum concentrations above background in adults living near contamination hotspots in Sweden

Contaminated drinking water (DW) is a major source of exposure to per- and polyfluoroalkyl substances (PFAS) at locations around PFAS production/use facilities and military airports. This study aimed to investigate quantitative relationships between concentrations in DW and serum of nine perfluoroalkyl acids (PFAAs) in Swedish adult populations living near contamination hotspots. Short-chained (PFPeA, PFHxA, PFHpA, and PFBS) and long-chained PFAAs (PFOA, PFNA, PFDA, PFHxS and PFOS) were measured in DW and serum. We matched DW and serum concentrations for a total of 398 subjects living or working in areas receiving contaminated DW and in one non-contaminated area. Thereafter, linear regression analysis with and without adjustments for co-variates was conducted. This enabled to derive (i) serum concentrations at background exposure (CB) from sources other than local DW exposure (i.e. food, dust and textiles) at 0 ng/L DW concentration, (ii) population-mean PFAA serum:water ratios (SWR) and (iii) PFAA concentrations in DW causing observable elevated serum PFAA concentrations above background variability. Median concentrations of the sum of nine PFAAs ranged between 2.8 and 1790 ng/L in DW and between 7.6 and 96.9 ng/mL in serum. DW concentration was the strongest predictor, resulting in similar unadjusted and adjusted regression coefficients. Mean CB ranged from <0.1 (PFPeA, PFHpA, PFBS) to 5.1 ng/mL (PFOS). Serum concentrations increased significantly with increasing DW concentrations for all PFAAs except for PFPeA with SWRs ranging from <10 (PFHxA, PFHpA and PFBS) to 111 (PFHxS). Observed elevated serum concentrations above background variability were reached at DW concentrations between 24 (PFOA) and 357 ng/L (PFHxA). The unadjusted linear regression predictions agreed well with serum concentrations previously reported in various populations exposed to low and high DW levels of PFOA, PFHxS and PFOS. The quantitative relationships derived herein should be helpful to translate PFAA concentrations in DW to concentrations in serum at the population level.

Antibiotics in Groundwater and River Water of Białka—A Pristine Mountain River

Antibiotics are emerging pollutants of great concern, due to detrimental effects of their sublethal concentrations on microbial communities. Monitoring of antibiotics’ presence and concentrations in the aquatic environment is of fundamental importance to the management of water resources. This study was aimed at filling the knowledge gap in terms of presence and concentration of antibiotics in surface water and groundwater in one of the mountain regions in southern Poland. The detailed aims included the assessment of whether there are spatial and/or temporal trends in antibiotic occurrence in water and the investigation of causes behind the changes in antibiotic concentrations. The study was conducted in seven sites (two groundwater and five river water) along the Białka river valley. Antibiotics were subjected to solid-phase extraction, followed by UHPLC/MS detection. Clindamycin, erythromycin, ofloxacin and trimethoprim were the most frequently detected, while the highest concentrations were observed for oxytetracycline and clindamycin. No antibiotics were detected in only one of the groundwater sites. Sewage treatment plant effluent was the hotspot of antibiotic contamination of the river downstream. The detection rates of antibiotics in the examined region seem to be driven mainly by the stability of antibiotics in the environment.

Hotspots of geogenic arsenic and manganese contamination in groundwater of the floodplains in lowland Amazonia (South America)

Arsenic enrichment in groundwater resources in deltas and floodplains of large sediment-rich rivers is a worldwide natural hazard to human health. High spatial variability of arsenic concentrations in affected river basins limits cost-effective mitigation strategies. Linking the chemical composition of groundwater with the topography and fluvial geomorphology is a promising approach for predicting arsenic pollution on a regional scale. Here we correlate the distribution of arsenic contaminated wells with the fluvial dynamics in the Amazon basin. Groundwater was sampled from tube wells along the Amazon River and its main tributaries in three distinct regions in Peru and Brazil. For each sample, the major and trace element concentrations were analyzed, and the position of the well within the sedimentary structure was determined. The results show that aquifers in poorly weathered sediments deposited by sediment-rich rivers are prone to mobilization and accumulation of aqueous arsenic and manganese, both in sub-Andean foreland basins, and in floodplains downstream. Two zones at risk are distinguished: aquifers in the channel-dominated part of the floodplain (CDF) and aquifers in the overbank deposits on the less-dynamic part of the floodplain (LDF). Some 70 % of the wells located on the CDF and 20 % on the LDF tap groundwater at concentrations exceeding the WHO guideline of 10 μg/L arsenic (max. 430 μg/L), and 70 % (CDF) and 50 % (LDF) exceeded 0.4 mg/L manganese (max. 6.6 mg/L). None of the water samples located outside the actual floodplain of sediment-rich rivers, or on riverbanks of sediment-poor rivers exceed 5 μg/L As, and only 4 % exceeded 0.4 mg/L Mn. The areas of highest risk can be delineated using satellite imagery. We observe similar patterns as in affected river basins in South and Southeast Asia indicating a key role of sedimentation processes and fluvial geomorphology in priming arsenic and manganese contamination in aquifers.

Lessons Learnt from the Revitalisation of Chemical Factory in Marktredwitz and River Banks Downstream: When ‘Renaturation’ Can Be Harmful

Our study addressed mercury contamination hotspots that originated from Chemical Factory Marktredwitz, Germany. The factory was abandoned in 1985 but its legacy has been persistently endangering the river ecosystem of the Ohře River, a Labe (Elbe) River tributary in the Czech Republic. We identified the timing for the peak contamination of fine sediments entering the Skalka Reservoir located on the Ohře River downstream of the Czech German boundary. Age constraints for the reservoir sediments were obtained using gamma spectrometry analyses of 137Cs and unsupported (excess) 210Pb. We also summarised historical and current Hg concentrations in suspended particulate matter in the Kössein–Röslau–Ohře river system and recent Hg concentrations in aquatic plants. Secondary contamination and its transfer to the Czech stretch of the Ohře River and the Skalka Reservoir through severely contaminated suspended material peaked during the period of factory closure and the start of remediation. The Hg contamination import to the Czech Republic is not likely to improve if the river is left without traditional management of bank reinforcement. This case study highlights a gap in safety regulations for the management of severely contaminated rivers and demonstrates the need to consider the role of historical contamination in river ‘renaturation’.

A proposed framework for the identification of indicator genes for monitoring antibiotic resistance in wastewater: Insights from metagenomic sequencing

Antibiotic resistance is one of the greatest threats to global human and animal health of our time. Municipal wastewater has been identified as a hotspot of antibiotic resistance contamination to water bodies. However, there are numerous potential antibiotic resistant pathogens and their associated antibiotic resistance genes (ARGs), making it difficult to implement routine monitoring that addresses the breadth of the problem. The objective of this study was to identify candidate indicator ARGs for monitoring antibiotic resistance in wastewater and receiving water bodies. We developed a framework to identify indicator ARGs that incorporated clinical relevance, abundance in wastewater, geographic ubiquity, environmental relevance, ARG mobility, associations with mobile genetic elements, and the availability of quantitative analytical methods. To identify indicator ARGs, published metagenomic sequencing data from 191 wastewater samples originating from 64 countries across the world were obtained from online public repositories. Through ARG annotation and network analysis, this framework revealed 56 candidate indicator ARGs distributed across four modules of strongly correlated ARGs, with one ARG from each module (oqxA, ermB, sul1, and mexE) proposed as a minimally redundant monitoring target. The results of this study provide the basis for antibiotic resistance surveillance and monitoring framework in wastewater and contaminated waterways.

Groundwater flow numerical model to evaluate the water mass balance and flow patterns in Groundwater Circulation Wells (GCW) with varying aquifer parameters

Groundwater Circulation Wells (GCW) can be an effective in-situ remediation option allowing high mass recovery of contaminants in cases where contamination hotspots are located in saturated soil having low hydraulic conductivity. Traditional treatment options such as Pump&amp;Treat, Air Sparging (AS)/Soil Vapor Extraction (SVE) and Multi Phase Extraction (MPE) typically require long operation times and significant costs for long-term plume management. GCWs induce meaningful changes in the groundwater flow introducing vertical flows both downward and upward, generating a “circulation cell”, which facilitates contaminant desorption from the soil. This study aims to understand the effects of a GCW on an aquifer in terms of both groundwater flow directions and water balance. A groundwater numerical model was built using MODFLOW-2005 to simulate the effect of the hydraulic parameters of the aquifer on the hydraulic circulation pattern of the GCW. The use of particle tracking simulated by MODPATH 7 showed the circulation cells and the impact on groundwater directions induced by different configurations of hydraulic parameters. The water flowing into the cell comes from both the injection well and the surrounding aquifer and the model shows how the hydraulic parameters of the aquifer, in particular the horizontal and vertical hydraulic conductivity, have a paramount influence in determining the shape and dimension of the circulation cell. A water mass balance analysis was carried out. It allowed to predict the groundwater flows exchanges between the GCW system and the surrounding aquifer, and to verify the sensitivity of the water budget to specific aquifer parameters. The results of this study are useful for further understanding the hydraulics of a GCW remediation system in order to support the design and to predict its performance.

Geospatial Assessment of Karst Spring Water Quality in Northeast Tennessee, USA

Karst springs are an essential source of private water supply for about 10% of households in Tennessee. However, the water quality of these springs is unmonitored and unregulated even though many springs are highly productive yet vulnerable to contamination. This study assesses spatial patterns in the water quality of roadside springs in northeast Tennessee. Karst spring water samples collected from 50 springs were assessed using EPA Standard methods for pathogens, nutrients, radon, and physicochemical parameters. From statistical and spatial analyses, all but five samples contained E. coli, while all samples contained fecal coliform. High E. coli was spatially clustered (Local Moran’s I = 0.177, pseudo p-value = 0.012) in regions of high agricultural land use, resulting in a fecal contamination hot spot on the border of Washington and Sullivan Counties, Tennessee. Radon concentrations exceeded the 300 pCi/L proposed MCL in 29 (58%) of springs, with one spring in Unicoi County exceeding 1000 pCi/L. A radon hot spot was identified in northern Washington County (Local Moran’s I = 0.160, pseudo p-value = 0.014). Cokriging of E. coli with land use and radon with distance to mapped fault did not improve interpolation models for either parameter. Other parameters, including nitrate, pH, and total dissolved solids, were within recommended ranges for drinking water. This snapshot of spring water quality status identifies areas of poor spring water quality of which spring water users in the region should be aware, and establishes the need for longitudinal sampling of spring water quality in contamination hot spots.

Spatial distribution and pattern of heavy metals in urban soils of Yogyakarta, Indonesia

Heavy metals contamination is becoming a global problem in urban areas. With that, understanding spatial distribution and pattern of heavy metals in urban soils is a crucial step toward sustainable urban development. This study intends to assess the spatial distribution and pattern of four heavy metals (Pb, Cu, Zn, and Cd) in Yogyakarta City outward in the boundaries of Sleman and Bantul Regencies. In relation, we utilized geostatistical method Empirical Bayesian Kriging (EBK) then correlated to Land Cover/Use data for the spatial analysis of heavy metals concentration. The degree of contamination was quantified using indices - PI (Pollution Index), Igeo (Geo-accumulation Index), and PLI (Pollution Load Index). We show that by analysing the Pb, Cu, Zn, and Cd elements of 168 urban soils samples collected, Yogyakarta City, a densely populated area, serves as a place of heavy metals contamination hotspots. Pb and Cu is posed as moderately contaminated, whereas Zn and Cd is considered as uncontaminated (as majority of Zn and Cd values does not exceed the background values). But in overlapping consideration of four heavy metals contamination, they are classified as moderately contaminated (PLI=1.10). In summary, heavy metals contamination in soils varies as a function of urbanization.

Pollution Characteristics, Spatial Distribution, and Health Risk Assessment of Soil Heavy Metal(loid)s in Panxi District, Southwest China: A Typical Industrial City

ABSTRACT This study collected 49 topsoil samples in agricultural soil from Panxi district (Sichuan, China), investigating the contamination status and probabilistic health risk of their heavy metal(loid)s (HMs). The average concentrations (mg/kg) of As, Cd, Cr, Cu, Ni, Pb and Zn were 18.18, 1.66, 294.05, 143.37, 70.18, 31.70 and 139.18, respectively. The pollution index (Pi) of the seven HMs were in the descending order of Cd > Cr > Cu > As > Zn > Ni > Pb, and the comprehensive Nemeiro risk index (PN) was 2.67, indicating that the study area was a moderate pollution by HMs. Meanwhile, Cd showed major contribution to the soil pollution among these HMs. The spatial distribution of HMs revealed that the southwestern part of the study area was the contamination hotspots. The hazard index (Hi) for children and adults were 1.621 and 0.346, respectively, and the total non-carcinogenic risk for children exceeded the threshold of 1. The carcinogenic risks associated with Cr (adults:, children:) and Ni (adults:) far exceeded the safe level of 1E-04; Monte Carlo simulations showed that humans locating in the study area suffered from a relatively significant carcinogenic risk; and the children were at higher risk than the adults. Among the three exposure pathways (ingestion, inhalation, and dermal contact), the ingestion was the most important way for HMs to harm human health. Overall, this study provides a scientific basis for both controlling HMs contamination and reducing the potential health risks in studied soils.

Ecological risk assessment of metal and hydrocarbon pollution in sediments from an urban tropical estuary: Tijuca lagoon (Rio de Janeiro, Brazil).

Urban tropical lagoons are often impacted by eutrophication, metal, and polycyclic aromatic hydrocarbon (PAH) contamination, but the toxicity of their bottom sediments is still poorly investigated in South America. Aiming to contribute to filling this gap, a sediment quality assessment was conducted in the Tijuca Lagoon (Rio de Janeiro, Brazil) using different lines of evidence (LOEs) including sediment characterization, determination of metals and PAHs, and acute toxicity testing with burrowing amphipods (Tiburonella viscana). Mud and organic matter contents played a crucial role in contaminant distribution along the lagoon. The concentrations of PAH were generally low (mean ΣPAH = 795.42 ± 1146.2ng/g; n = 23), but a contamination hotspot of light PAH compounds was identified. Such PAHs were mainly pyrolytic, probably related to the deposition of atmospheric pollution, although petrogenic compounds also occur in the lagoon. The data indicated the occurrence of geochemical anomalies of Zn, Cu, Pb, and Hg (mean values = 176.9 ± 91.6, 45.1 ± 21.3, 35.2 ± 15.0, 0.1442 ± 0.0893mg/kg, respectively; n = 23), probably associated with industrial wastes, garbage deposition, urban runoff, and domestic sewage contributions. The mortality of T. viscana was significant for more than 85% of the samples (mean mortality = 70.3 ± 26.0%; n = 23), but it was not significantly correlated with PAH and metal concentrations. On the other side, domestic sewage contributions and eutrophication seem to play a relevant role in sediment toxicity. Actually, the toxicity observed in the tests seems to be due to the simultaneous influence of multiple toxicants and their combined effects on the organisms. Such stressors may include not only metals, PAH, and eutrophication but also chemicals not evaluated in this study, such as hormones, pharmaceuticals and personal care compounds, perfluorocompounds, detergents, and others.

Diagnosing trace metals contamination in ageing stormwater constructed wetlands by portable X-ray Fluorescence Analyzer (pXRF)

In the context of stormwater management in urban areas, more knowledge is needed about sustainable urban drainage systems (SUDS)' long-term performance. This article reports robust calibration of a portable X-ray Fluorescence Analyzer (pXRF) for a purpose of metal accumulation diagnosis in two stormwater constructed wetlands (SCWs). Two 9-year-old SCWs located in Eastern France and composed of a sedimentation pond and a vertical-flow reed-bed filter (RBF#1) respectively a horizontal-flow RBF (RBF#2) are studied. A focus is made on the RBFs where five target metals (Cr, Cu, Ni, Pb, Zn) are monitored to fulfill three objectives: i) develop a robust analyzing method for both field and laboratory scale; ii) compute a distribution mapping of the metals on the substrate; and iii) identify and quantify contamination hotspots. pXRF measurements present an opportunity for a quick field diagnosis of such ageing systems once calibrated. An optimal 63 s beam shooting time was selected for analyses, and optimal particle size distribution was set below 250 μm. As water content is known to be a critical factor influencing measuring quality, correction factors were determined to allow for field campaign up to 30 % of water content. Metals are more accumulated in RBF#1 than in RBF#2 because of the particle size distribution and hydraulic regime of the RBFs. Moreover, RBF#1 displays a higher metal accumulation at the water supply outputs while the distribution pattern in RBF#2 is more diffuse. Only 34 %, resp. 22 % of RBF#1 and RBF#2 surface is contaminated, with corresponding concentrations ranging among the highest 50 % and 25 % concentrations. Eventually, the RBF#1 upper layer (0–5 cm) higher organic matter content generates more metal retention than its deeper layer whereas in RBF#2 metal concentration is homogeneous along depth. These results can be useful to optimize the long-term maintenance and possibly the sizing of such systems.

Spatiotemporal urban water profiling for the assessment of environmental and public exposure to antimicrobials (antibiotics, antifungals, and antivirals) in the Eerste River Catchment, South Africa.

Antimicrobial agent (AA) usage, excretion, and persistence are all important factors in association with the occurrence and dissemination of antimicrobial resistance. Urban water profiling was utilised in the Eerste River catchment (South Africa) to establish AA usage in a region where comprehensive prescription records were not readily available and where portions of the community did not have sufficient access to sanitation. This technique enabled the environmental exposure to be quantified throughout the catchment area and the identification of contamination hotspots. Monitoring occurred over a 11-month period. 812 samples were processed using UPLC-MS/MS for the quantitation of 56 antimicrobials and 26 of their metabolites. Spatiotemporal trends were established, with consideration to community behaviour, seasonal changes, and physiochemical properties of the analytes. The Eerste River samples collected upstream from the town of Stellenbosch had the lowest AA loads (<4 g/day), unafflicted by industrial presence and with only small impact from farming activities. This was followed by sites downstream from a wastewater treatment plant (serving 178K people). The measurement of low AA loads (influent: 500-800g/day and effluent 50-100g/day), indicates a high efficiency of wastewater treatment, allowing for an effective reduction of AA and a lower environmental burden. This is compared to river sites that receive untreated waste from communities in informal settlements (6-12K people) that are not connected to the sewer infrastructure (with AA levels accounting for 100-600g/day). Temporal trends exhibited reduced daily loads during the summer to early autumn (Nov-May). This is likely due to seasonal patterns in community health and/or notable changes in rainfall and temperatures at the sampling locations throughout the year. However, weather patterns are also important to consider - particularly for the river sites. South Africa has notable rainfall and temperature seasonality. Antiretrovirals (ARV), emtricitabine and lamivudine, were the most prevalent drugs throughout the monitoring campaign, followed by tuberculosis drugs and sulfonamides. ARVs were, however, effectively reduced via wastewater treatment processes (>97%). This was also the case for beta-lactams, nitrofurantoin, and trimethoprim. The treatment efficacy for other drugs was more variable, that did not appear to have temporal significance.

Perinatal Dioxin Exposure and Attention Deficit Hyperactivity Disorder (ADHD) Symptoms in Children Living in a Dioxin Contamination Hotspot in Vietnam.

We examined children in Da Nang, a dioxin contamination hotspot in Vietnam, twice at 5 and 8 years of age, and investigated sex- and age-dependent differences in the effects of dioxin exposure on attention deficit hyperactivity disorder (ADHD) symptoms. We also studied autistic traits in children with ADHD symptoms. A total of 163 children participated in follow-up surveys at 5 and 8 years of age and were included in the present analysis. ADHD symptoms were assessed using an ADHD rating scale with inattention and hyperactivity-and-impulsivity (hyperactivity) subscales. Autistic behaviors were evaluated using the Autism Spectrum Rating Scale (ASRS). Perinatal dioxin exposure was indicated by dioxin levels in maternal breast milk. In boys, hyperactivity scores were significantly higher in the high 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) group only at 5 years of age. In girls, hyperactivity scores at 8 years of age were significantly higher in the high TCDD group, which was significantly associated with those at 5 years of age. In girls, ASRS unusual behavior scores were significantly higher with higher TCDD exposure and hyperactivity scores at 8 years of age. These results suggest that high perinatal TCDD exposure may increase ADHD likelihood and autistic traits, particularly in girls of 7–8 years of age.

The application of sediment quality guidelines and toxicity assessment to identify contaminant hotspots in an urbanised West Australian estuary.

This paper presents a tiered assessment approach that enabled identification, triage, interrogation and confirmation of significantly contaminated areas of an urbanised West Australian estuary. The spatial distribution of organochlorine pesticides (OCPs), polycyclic aromatic hydrocarbons (PAHs) and bioavailable metals was determined in surficial sediments of the Swan-Canning Estuary through broad-scale screening (500 cores, 100 composite samples, 20 locations). The application of sediment quality guideline values (SQGVs) enabled ranking of locations through risk-based scoring and identification of contaminant hotspots. Subsequent targeted ecotoxicological and chemical assessment was undertaken at the highest scoring location in each tributary (80 cores, 16 composite samples, 3 locations, 16 sites). In the Canning tributary, Bull Creek sediments demonstrated the highest metal concentrations and greatest number of SQGVs exceeded. High-level toxicity was experienced in copepods and moderate toxicity in mussels (test sensitivity: copepod>mussel>amphipod). Toxicity-inducing contamination was attributable to two stormwater outfalls and limited to 300 m from points of discharge. In the Swan tributary, Claisebrook sediments demonstrated the highest concentrations of all PAHs, most OCPs and metals and the greatest number of SQGVs exceeded. High-level toxicity was reported in fish and mussels and moderate toxicity in copepods and amphipods (test sensitivity: fish>mussel>amphipod>copepod). Toxicity-inducing contamination included a stretch of estuary >1 km long, and two stormwater outfalls in the area were likely sources. The distribution and nature of PAH contamination suggested an additional source at Claisebrook. This combined chemistry and biological effects dataset provides critical information for the management of planned major development and concomitant estuary-bed disturbance in the coming decade.

Aerosol morphology and particle size distribution in orthopaedic bone machining: a laboratory worst-case contamination simulation. Is high-speed bone machining potentially harmful by pollution and quality schemes and what measures could be taken for prevention?

Aim of the studyHigh-speed bone machining devices with irrigation fluid were used in surgery to spread aerosols and toss tissue particles of varying morphology into the operating room. Based on measurements taken on a phantom object, the shape, size, and spatial contamination distribution of such particles were assessed.MethodCadaveric femoral heads were continuously machined with a spherical bur, manually held at a fixed attack angle. The irrigation fluid used during bone machining was enriched with bacteria to act as a tracer to quantify the spatial contamination. A vertical board equipped with snippets served as a phantom object to assess contamination load and morphology of airborne particles.ResultsEight-nine percent of the particles had a non-circular cross section. The detected particle size ranged across six orders of magnitude, from 0.006 to 4 mm2 with a median particle size of 0.125 mm2. The CFU counts observed after the standard machining time ranged from 7 to 240, with a median of 2 CFUs. The highest median contamination was seen at the upper right corner of the phantom.DiscussionThe experiments show that contaminating particles of a wide variety of shapes and sizes are part of the aerosol created by high-speed burring. While protection of personnel and equipment is always important, surgical helmets should be worn, especially at contamination hotspots, and gloves should be replaced at the end of machining. Sensitive instruments and measuring devices—such as optical sensors—should also be protected effectively, as the optical measurement may be obstructed by aerosol particles.

Adverse effects of dioxins on cognitive ability and motor performance of 5-year-old children residing in a hotspot of dioxin contamination originating from Agent Orange in Vietnam: A prospective cohort study

Bien Hoa airbase is the most dioxin-polluted hotspot in Vietnam. In 2012, a birth cohort living around Bien Hoa airbase was recruited for assessment of physical and neurological development. In the present study, neurodevelopment scores at 5 years of age were assessed by the Kaufman Assessment Battery for Children, Second Edition and the Movement Assessment Battery for Children, Second Edition for 185 children in Bien Hoa and 104 children in Ha Dong (unexposed control group) to clarify the effects of dioxin. 2,3,7,8-tetrachlorodibenzo-p-dioxin concentrations in breast milk of women in Bien Hoa were approximately three times higher than those of women in Ha Dong (2.33 vs. 0.69 pg/g fat, p < 0.001). In general, neurodevelopment scores were lower in Bien Hoa children than in Ha Dong children. In boys, scores differed for number recall (12.6 vs. 14.0, p = 0.036), triangles (10.7 vs. 12.4, p = 0.005), manual dexterity (8.3 vs. 9.7, p = 0.037), balance (7.4 vs. 10.3, p < 0.001), and total movement scores (8.0 vs. 10.1, p = 0.003). After adjusting for covariates, linear regression analysis indicated that the scores of the triangles, balance, and total movement tests were inversely associated with levels of 2,3,7,8-tetrachlorodibenzo-p-dioxin and of toxic equivalency of polychlorinated dibenzodioxins and polychlorinated dibenzofurans. In girls, scores differed for the triangles test (11.0 vs. 12.6, p = 0.005), hand movement test (9.6 vs. 11.3, p = 0.003), and balance test (9.1 vs. 10.7, p = 0.050); toxic equivalency of polychlorinated dibenzofurans was inversely associated with hand movement and balance scores. Overall, perinatal dioxin exposure appears to have a long-term impact on neurodevelopment.

Source apportionment and risk assessment of soil heavy metals around a key drinking water source area in northern China: multivariate statistical analysis approach.

With the intensive urbanization and industrialization in recent years, lots of products containing heavy metals (HMs) have brought in severe environment problems. Yuqiao Reservoir (YQR) is an important drinking water source area in Tianjin of China, and the soil environmental quality of YQR is vital for human health. The goal of this study was to identify the priority control pollutants and hotspots of HMs contamination of YQR catchment. Thus, an integrated field investigation was conducted to analyze the major elements such as As, Cd, Cr, Cu, Hg, Ni, Pb and Zn in soils around YQR. Geoaccumulation index (Igeo), enrichment factor (EF) and potential ecological risk index (PERI) were employed to assess the contamination status of HMs. The average contents of these elements were given as follows: As 7.97mg/kg, Cd 0.31mg/kg, Cr 86.1mg/kg, Cu 24.7mg/kg, Hg 0.044mg/kg, Ni 30.7mg/kg, Pb 27.3mg/kg and Zn 76.7mg/kg. According to geoaccumulation index (Igeo) and enrichment factor (EF) values, Cd, Cr, Pb and As showed a prominent enrichment. The result of multivariate statistics showed that Cd, Cr, Cu, As, Ni, Pb and Zn concentrations were mainly affected by human activities, whereas Hg was mainly from natural release. The anthropogenic activities were the major sources with a contribution of 91.46%, while natural origins only contributed 8.54%. And agricultural fertilization, mining and traffic activities are the most probable sources of these heavy metals in the soil. The PERI values indicated that 65.7% of total HMs were at low risk, 22.5% in moderate risk and 11.8% in considerable risk. To ensure soil environmental quality and human health, cadmium should be listed as a priority control pollutant. Spatial maps of HMs and their integrated PERI provided clear hotspots that indicated lower risk in the region close to YQR but higher risk in the region far from YQR.