Potential Human Health Effects Research Articles

Dicamba use and cancer incidence in the agricultural health study: an updated analysis.

The herbicide dicamba has been commonly used agriculturally and residentially. Recent approval of genetically engineered dicamba-resistant crops is expected to lead to increased dicamba use, and there has been growing interest in potential human health effects. A prior analysis in the Agricultural Health Study (AHS) suggested associations between dicamba and colon and lung cancer. We re-evaluated dicamba use in the AHS, including an additional 12 years and 2702 exposed cancers. The AHS is a prospective cohort of pesticide applicators in Iowa and North Carolina. At enrollment (1993-1997) and follow-up (1999-2005), participants reported dicamba use. Exposure was characterized by cumulative intensity-weighted lifetime days, including exposure lags of up to 20 years. We estimated relative risks (RR) and 95% confidence intervals (CI) using multivariable Poisson regression for incident cancers diagnosed from enrollment through 2014/2015. Among 49922 applicators, 26412 (52.9%) used dicamba. Compared with applicators reporting no dicamba use, those in the highest quartile of exposure had elevated risk of liver and intrahepatic bile duct cancer (nexposed = 28, RRQ4 = 1.80, CI: 1.26-2.56, Ptrend < 0.001) and chronic lymphocytic leukaemia (CLL, nexposed = 93, RRQ4 = 1.20, CI: 0.96-1.50, Ptrend = 0.01) and decreased risk of myeloid leukaemia (nexposed = 55, RRQ4 = 0.73, CI: 0.51-1.03, Ptrend = 0.01). The associations for liver cancer and myeloid leukaemia remained after lagging exposure of up to 20 years. With additional follow-up and exposure information, associations with lung and colon cancer were no longer apparent.In this first evaluation of liver and intrahepatic bile duct cancer, there was an association with increasing use of dicamba that persisted across lags of up to 20 years.

Characterisation of semi-volatile hydrocarbon emissions from diesel engines

Exhaust emissions from diesel vehicles have recently been receiving global attention, due to potential human health effects associated with exposure to emitted pollutants. In addition, a link has recently been established between unburnt hydrocarbon (HC) emissions from diesel engines and photochemical smog. Despite being present at very low concentrations in the exhaust, these HCs may act as precursors in the formation of photochemical smog pollution. While short-chain HCs are easier to characterise and have been successfully reduced in many developed cities, longer chain HCs, most likely arising from diesel exhaust emissions, have been poorly quantified and to date, a limited range of HCs from this source has been studied. In this study, transient cycle tests were conducted to collect exhaust emissions from a Euro 3 compliant, 1.6 L test engine fuelled with three diesel fuels (SAM10, PAR10, and EUR10), using portable denuder samplers which were analysed by thermal desorption-comprehensive 2D gas chromatography-time of flight mass spectrometry (TD-GC x GC-TofMS). The SAM10 diesel had the greatest n-alkane emissions with greater emissions observed in the earlier phases (low and medium phase) of the WLTC test cycle. PAR10 diesel had the second highest n-alkane emissions and EUR10 had the lowest n-alkane emissions amongst the three fuels. Substituted alkyl-benzenes were also detected in the gas phase emissions from each fuel. The results showed that long-chain HCs were present at easily detectable concentrations in diesel engine exhaust emissions, which is critical in understanding their contribution to photochemical ozone and informing appropriate mitigation and management strategies.

Environmental exposure to microplastics: a scoping review on potential human health effects and knowledge gaps

Background: Microplastics are fast becoming a major global environmental contaminant. Little is known about the health effects of microplastic exposure to humans despite being omnipresent in all spheres of life and ecology. This scoping review explores the existing evidence of potential human health effects of microplastics and subsequent knowledge gaps. Methods: An electronic search of published articles in PubMed, Scopus, EMBASE, Cochrane databases, and Google Scholar was conducted, using a combination of subject headings and keywords for microplastics and human health effects. Documents only published in English between 2004 and March 2020 were included. A grey literature search was conducted following a comprehensive checklist in Google Scholar and the environmental organization websites. The initial search resulted in 17,043 published articles and grey literature. After a full review of published articles and their references, 125 publications were identified for further detailed review. Throughout the screening process, every document was reviewed by at least two of the researchers. Results: These articles indicate that human exposure to microplastics might occur through ingestion, inhalation, and dermal contact due to its presence in food, water, air, and consumer products. Microplastics exposure can cause particle toxicity through oxidative stress, inflammatory lesions, and increased uptake or translocation. Several studies have demonstrated the potentiality of metabolic disturbances, neurotoxicity, increased cancer risk, and reproductive toxicity in humans. Moreover, microplastics were found to release their constituent compounds and those adsorbed onto its surface in human tissues. Conclusion: Knowledge of microplastic toxicity on human health is still limited. Further research is needed to quantify the effect of microplastics on human health and pathogenesis.

In Vitro Aerosol Exposure to Nanomaterials: From Laboratory to Environmental Field Toxicity Testing.

Exposure to nanomaterials (NMs) is inevitable, requiring robust toxicological assessment to understand potential environmental and human health effects. NMs are favored in many applications because of their small size; however, this allows them to easily aerosolize and, subsequently, expose humans via inhalation. Toxicological assessment of NMs by conventional methods in submerged cell culture is not a relevant way to assess inhalation toxicity of NMs because of particle interference with bioassays and changes in particokinetics when dispersed in medium. Therefore, an in vitro aerosol exposure chamber (AEC) was custom designed and used for direct deposition of NMs from aerosols in the environment to the air-liquid interface of lung cells. Human epithelial lung cell line, A549, was used to assess the toxicity of copper, nickel, and zinc oxide nanopowders aerosolized by acoustic agitation in laboratory study. Post optimization, the AEC was used in the field to expose the A549 cells to NM aerosols generated from firing a hand gun and rifle. Toxicity was assessed using nondestructive assays for cell viability and inflammatory response, comparing the biologic effect to the delivered mass dose measured by inductively coupled plasma-mass spectrometry. The nanopowder exposure to submerged and ALI cells resulted in dose-dependent toxicity. In the field, weapon exhaust from the M4 reduced cell viability greater than the M9, while the M9 stimulated inflammatory cytokine release of IL-8. This study highlights the use of a portable chamber with the capability to assess toxicity of NM aerosols exposed to air-liquid interface in vitro lung cell culture.

Arsenic in edible macroalgae: an integrated approach

ABSTRACTArsenic is a metalloid naturally present in marine environments. Various toxic elements including arsenic (As) are bioaccumulated by macroalgae. This metalloid is subsequently incorporated as arsenate into the organism due to similarity to phosphate. In recent decades, the use of macroalgae in food has increased as a result of their numerous benefits; however, As consumption may exert potential consequences for human health. The objective of this review was to discuss the articles published up to 2019 on As in seaweed, including key topics such as speciation, toxicity of the most common species in marine macroalgae, and their effects on human health. Further, this review will emphasize the extraction methods and analysis techniques most frequently used in seaweed and the need to develop certified reference materials (CRMs) in order to support the validation of analytical methodologies for As speciation in macroalgae. Finally, this review will discuss current legislation in relation to the risk associated with consumption. The number of articles found and the different approaches, biological, analytical and toxicological, show the growing interest there has been in this field in the last few years. In addition, this review reveals aspects of As chemistry that need further study, such as transformation of organic metalloid species during digestion and cooking, which necessitates analytical improvement and toxicological experiments. Taken together our findings may contribute to revision of current legislation on As content in edible seaweed relating to human health in a growing market.

Potential Human Health Effects Associated with Unconventional Oil and Gas Development

PDS 64: Health impact assessment and environmental justice, Johan Friso Foyer, Floor 1, August 26, 2019, 1:30 PM - 3:00 PM Background: Unconventional oil and natural gas development (UOGD) has expanded rapidly in the last decade. Accompanying this expansion is a growing body of scientific literature about its potential for exposure and health effects. We present a review of the relevant epidemiologic literature and offer a research path forward to resolve questions that remain. Methods: The Health Effects Institute’s (HEI) Energy Research Committee (the Committee), consisting of multidisciplinary experts from across the U.S., along with HEI staff critically reviewed analytical epidemiology studies published between January 2000 and December 2018 with an objective of exploring relationships between environmental exposures originating directly from UOGD in the United States and human health outcomes. The Committee systematically assessed strengths and limitations of each study and the overall body of literature by health outcome. The Committee developed a set of research needs following its assessment. Results: The twenty-five epidemiology studies reported associations between surrogate measures of UOGD exposure and perinatal, respiratory, and cardiovascular outcomes, cancer, and various symptoms. Studies employed different study designs and reported inconsistent findings. The passage of only a few years since the rapid growth of UOGD marks an early phase of exploratory research; thus, the Committee notes that investigators typically made thoughtful use of available data to re-construct potential UOGD exposures and assess health outcomes. The Committee recommends further study to improve on methodologic limitations noted in its review, in particular, careful control of confounding and improved exposure assessment approaches that include enhanced characterization of spatial and temporal variability and measurements of chemical and non-chemical agents originating from UOGD. Conclusions: To better characterize potential UOGD-related exposures, a main limitation identified in the body of epidemiology studies, the Committee conducted a review of the exposure literature related to UOGD. Results from both literature reviews have informed planning efforts for population-level exposure research.

Comparative analysis of urban road dust compositions in relation to their potential human health impacts

This study investigated the chemical components of fine urban road dust from seven sampling sites, based on which we could predict potential human health effects. The elemental compositions, including the contents of metals and volatile or semivolatile organic compounds, were determined to establish comprehensive chemical profiles of solid road dust. The chemical profiles, consisting of C: H ratio, metal contents, and relative abundances of organic compounds, provided a chemical signature for road dust. To overall cytotoxicity values ranging between 7 and 58%, water extracts contributed less than 15%, and cell death mainly occurred via direct contact with solid-phase components, which possibly indicates that the selected chemical profile of solid-phase road dust components could serve as a strong predictor for BJ and WI-38 cytotoxicity. Pure metal oxides (Cr2O3, CuO, Fe2O3, MnO2, NiO, or ZnO) exhibited a positive dose-response, and the corresponding metal contents in solid road dust were well correlated with cell viability. The principal component analysis (PCA) results suggested that the metal contents were stronger predictors of cytotoxicity than the benzene derivative or hydrocarbon contents. The chemical profiles established in this study could be further utilized to identify candidate health hazard factors in road dust.

Multiorgan histopathological changes in the juvenile seabream Sparus aurata as a biomarker for zinc oxide particles toxicity.

Zinc oxide nanoparticles are widely used in some domains (cosmetics, pharmaceuticals optical devices, and agricultural field) due to their physical, optical, and antimicrobial properties. However, the release of ZnO-NPs into the environment may affect organisms like fish with potential consequences for human health. Histological approaches of the acute effects of these materials on fish are scarce; thus, the present study aimed to investigate the potential toxic effects of acute exposure to ZnO particles in marine environments, by assessing histological changes in the gills, liver, spleen, and muscle of gilthead seabream (Sparus aurata) juveniles. Thus, fish were exposed for 96 h, via water, to 1 mg L-1 of ionic zinc and zinc oxide particles (1.1, 1.2, and 1.4 μm of size). Histological examination revealed gills as the most affected organ, followed by liver, muscle, and spleen. In the gills, histopathological changes included hyperplasia of epithelial cells, fusion of the secondary lamellae, and lifting of the lamellar epithelium with edema. In the liver, lipid vacuolation of several degrees, necrosis of hepatic and pancreatic tissues, blood congestion in sinusoids and hepatoportal vessels, presence of cellular infiltrate, and melano-macrophages diffusion was found. Muscle showed degeneration, atrophy, thickening and necrosis of muscle fibers with edema between them, and presence of melano-macrophages in the muscle layer. Spleen was the less damaged organ, displaying congested blood, white pulp increase/rupture, and bigger and darker melano-macrophage aggregates in the splenic stroma. These results underline that the size of particles plays a determinant role in their potential pernicious effects. A short-term exposure caused major histopathological changes in relevant organs of S. aurata juveniles, possibly affecting their function.

Parasites and Metals in Walleye (Sander vitreus) and Northern Pike (Esox lucius) from Boreal Montreal Lake (Saskatchewan, Canada): Assessment of Human Health Risks.

Industrial activities conducted in Northern Canada have raised concerns among Indigenous communities regarding wildlife contamination and potential consequences for human health. Therefore, an investigation on the chemical (metals/metalloids) and biological (parasite) burden of adult walleye (Sandervitreus) and northern pike (Esoxlucius) from Montreal Lake, Saskatchewan, was conducted to assess health risks related to fish consumption. Dissection revealed that both fishes displayed typical parasite communities, with Eubothrium sp. (Cestoda) and Raphidascarisacus (Nematoda) occurring the most frequently. None of the identified parasite species were infectious to humans. Concentrations of most inorganic contaminants in fish muscle were low and both walleye and pike can be considered healthy components of a balanced diet. However, due to slightly elevated mercury concentrations, excessive daily consumption of these fishes is not recommended, as mercury exposure over time may lead to adverse health effects.

Targeted GC-MS analysis of firefighters’ exhaled breath: Exploring biomarker response at the individual level

Biomarker measurements can provide unambiguous evidence of environmental exposures as well as the resultant biological responses. Firefighters have a high rate of occupational cancer incidence, which has been proposed to be linked in part to their increased environmental exposure to byproducts of combustion and contaminants produced during fire responses. In this article, the uptake and elimination of targeted volatile organic compounds were investigated by collecting the exhaled breath of firefighters on sorbent tubes before and after controlled structure burns and analyzing samples using automated thermal desorption-gas chromatography (ATD-GC/MS). Volatile organic compounds exposure was assessed by grouping the data according to firefighting job positions as well as visualizing the data at the level of the individual firefighter to determine which individuals had expected exposure responses. When data were assessed at the group level, benzene concentrations were found to be elevated post-exposure in both fire attack, victim search, and outside ventilation firefighting positions. However, the results of the data analysis at the individual level indicate that certain firefighters may be more susceptible to post-exposure volatile organic compounds increases than others, and this should be considered when assessing the effectiveness of firefighting protective gear. Although this work focuses on firefighting activity, the results can be translated to potential human health and ecological effects from building and forest fires.

A single indicator of noxiousness for people and ecosystems exposed to stable and radioactive substances

Inspired by methods used for life cycle impact assessment (LCIA), we constructed a series of indicators to appreciate the noxiousness of radioactive materials and wastes for human and ecosystem health. According to known potential human health and ecological effects of such materials, six main impact categories were considered to initiate the development of the method: human cancer and non-cancer effects vs. ecotoxicity, considering both chemotoxicity and radiotoxicity. For ecosystems, the noxiousness indicator is based on the concept of Potentially Affected Fraction (PAF), used as a damage indicator at the ecosystem level. The PAF express the toxic pressure on the environment due to one substance. It has been enlarged to mixtures of substances as multi-substances PAF (ms-PAF), and applied to a mix of stable and radioactive substances. Combining ecotoxicity data and a simplified model of exposure of fauna and flora, we proposed a chemotoxicity indicator and a radiotoxicity indicator, ultimately aggregated into a single indicator simply by addition.According to acknowledged practices in LCIA and corresponding available data, we suggested implementing to human health an approach similar to that applied to ecosystems. We produced eigth basic indicators combining effects categories (cancer and non cancer), exposure pathways (ingestion and inhlation) and substances (chemicals and radionuclides). The principle of additivity supporting the whole proposed approach allows their complete aggregation into a single indicator also for human health. Different source terms may be then easily directly compared in terms of human and ecological noxiousness.Applied to the time evolution of a High Level radioactive Waste (HLW), the method confirmed over 1 million years the dominance of the radiotoxicity in the noxiousness of the material for both humans and environment. However there is a change with time in the ranking of the most noxious substances, with stable metals contribution going progressively up. Finally, the HLW global noxiousness, integrating human health and ecological aspects, was assessed through time at three stages and showed a temporal decrease as expected from the dominance of the radiotoxicity.

Heavy metal accumulation in frogs surrounding an e-waste dump site and human health risk assessment

This study was performed heavy metals (As, Cd, Cr, and Pb) in water, soil and frogs around an electronic-waste dump site. The bioaccumulation factors (BAFs) of heavy metals in three frog species and potential human health risks were assessed. Heavy metals were analyzed using inductively coupled plasma-optical emission spectrometry. The Cd and Pb concentrations in water samples and As and Pb concentrations in soil samples from within the e-waste dump site exceeded the standards. The heavy metal concentrations in the muscles of three frog species were as follows: Cr > Pb > As > Cd, and there were no significant differences among frog species except in the case of Pb (p < 0.05). Only the Cr concentrations exceeded the food quality standards. The relative order of the BAFs for heavy metals in frogs as a result of uptake from the water and soil was Cr > As > Pb > Cd and Cr > As > Cd > Pb, respectively, which indicated that the uptake from water was greater than that from the soil. The assessment of the health risk index and carcinogenic risk (CR) indicated potential human health effects from As, Cr, and Pb via the consumption of frogs.

Quantifying association between liver tumor incidence and early-stage liver weight increase - An NTP data analysis.

Two-year toxicology and carcinogenesis rodent studies conducted at the National Toxicology Program (NTP) are used to identify potential adverse health effects in humans due to chemical exposure, including cancer. Liver tumor, the most frequently diagnosed tumor type of chemically induced neoplastic effects documented in NTP's carcinogenicity studies, is usually difficult to be detected at early stage due to the inconspicuous symptoms. However, the abnormal growth of liver cells can lead to liver weight increase, so it is hypothesized that liver tumor incidence is associated with early stage liver weight increase. In this study, the association between liver weight increase and liver tumor incidence are quantified by (1) calculating the correlation coefficient of and (2) building quantitative linear relationship between benchmark dose estimates derived from these two types of data collected from NTP studies. Together with 151 chemical/species/sex combinations of liver tumor data showing positive evidence collected from 76 NTP long-term studies, short-term liver weight data reported in the same NTP report were extracted to be paired with the liver tumor data for the analyses. Results show that the estimated correlation coefficients (as high as 0.78) along with the adequately fitted linear models suggest that the association between relative liver weight increase and aggregated liver tumor incidence are relatively strong. Additional analyses focused on some more specific situations (e.g., specific tumor type or specific strain/sex combination) further confirmed the strong association. Given the design of this study, the interpretation of the findings is not that liver weight increase can be used to predict liver tumor incidence, instead, evident increase in liver weight might be used as a reason to prioritize the test article for a two-year toxicology and carcinogenesis study.

Occurrence, sources, human health impacts and mitigation of microplastic pollution.

The presence and accumulation of plastic and microplastic (MP) debris in the natural environment is of increasing concern and has become the focus of attention for many researchers. Plastic debris is a prolific, long-lived pollutant that is highly resistant to environmental degradation, readily adheres hydrophobic persistent organic pollutants and is linked to morbidity and mortality in numerous aquatic organisms. The prevalence of MPs within the natural environment is a symptom of continuous and rapid growth in synthetic plastic production and mismanagement of plastic waste. Many terrestrial and marine-based processes, including domestic and industrial drainage, maritime activities agricultural runoff and wastewater treatment plants (WWTPs) effluent, contribute to MP pollution in aquatic environments. MPs have been identified in food consumed by human and in air samples, and exposure to MPs via ingestion or inhalation could lead to adverse human health effects. Regulations in many countries have already been established or will soon be implemented to reduce MPs in aquatic environments. This review focuses on the occurrence, sources, and transport of MPs in terrestrial and aquatic environments to highlight potential human health effects, and applicable regulations to mitigate impacts of MPs. This study also highlights the importance of personality traits and cognitive ability in reducing the entry of MPs into the environment.

Toxicity profiling of flame retardants in zebrafish embryos using a battery of assays for developmental toxicity, neurotoxicity, cardiotoxicity and hepatotoxicity toward human relevance

Following the voluntary phase-out of brominated flame retardants (BFRs) due to their environmental persistence and toxicity, the organophosphorus flame retardants (OPFRs) are emerging replacements. However, there is limited information on the potential human health effects of the OPFRs. Zebrafish embryos are a viable vertebrate model organism with many advantages for high throughput testing toward human hazard assessment. We utilized zebrafish embryos to assess developmental toxicity, neurotoxicity, cardiotoxicity and hepatotoxicity, of eight replacement OPFRs: (triphenyl phosphate [TPHP], isopropylated phenyl phosphate [IPP], 2-ethylhexyl diphenyl phosphate [EHDP], tert-butylated phenyl diphenyl phosphate [BPDP], trimethyl phenyl phosphate [TMPP], isodecyl diphenyl phosphate [IDDP], tris(1,3-dichloroisopropyl) phosphate [TDCIPP], and tris(2-chloroethyl) phosphate [TCEP]) and two BFRs (3,3′,5,5′- tetrabromobisphenol A [TBBPA] and 2,2′4,4′-brominated diphenyl ether [BDE-47]). To determine potential effects on teratogenicity, embryos were exposed to flame retardants (FRs) at 4 h post fertilization (hpf) to 4 days post fertilization (dpf) and morphological alterations and corresponding survival were evaluated at 2 and 4 dpf. Internal concentrations were measured in larvae used in this assay by liquid chromatography-mass spectrometry. Locomotor activity was assessed in larvae treated for 48 h (from 3 dpf to 5 dpf), followed by hepatotoxicity evaluation. Finally, alterations in heart rate and rhythmicity were assessed to determine cardiotoxicity in 48 hpf embryos exposed to compounds for 3 h. Results suggest that several OPFRs (BPDP, EHDP; IPP, TMPP; TPHP and TDCIPP) produced adverse effects in multiple target organs at concentrations comparable to the two BFRs. As these OPFRs have the capacity to disrupt an integrated vertebrate model, they potentially have the capacity to affect mammalian biology. Then, we compared the lowest effective levels (LEL) in zebrafish with estimated or measured human plasma concentrations using biomonitoring data (human plasma, breast milk, handwipe samples and house dust) and a high throughput toxicokinetic (HTTK) model. Results indicate that for some compounds, the nominal LELs were within the range of human exposures, while internal LELs in zebrafish are above internal exposures in humans. These findings demonstrate the value of the zebrafish model as a relevant screening tool and support the need for further hazard characterization of the OPFRs.

Dietary Fumonisin and Growth Impairment in Children and Animals: A Review.

Fumonisins are mycotoxins produced primarily by the fungi Fusarium verticillioides and F. proliferatum, which colonize maize in tropical, subtropical, and temperate climates worldwide. Fumonisin exposure is the highest in rural populations that consume large amounts of maize and maize products. Among them, infants and young children are the most vulnerable when they are weaned onto maize-based foods. Therefore, it is critical to understand the impact of fumonisin on children's health and growth. This review describes the evidence linking fumonisin exposure to child growth impairment. First, toxicological studies that attempt to elucidate the mechanism by which fumonisin may impair growth are discussed. Next, a description is given of candidate biomarkers for accurately capturing fumonisin exposure in humans. Potential human health effects of fumonisin exposure beyond growth impairment, including esophageal cancer and neural tube defects (NTDs), are briefly described. We review epidemiological studies that collectively show an increasing weight of evidence linking fumonisin exposure to growth impairment, particularly in world regions where young children consume maize-based weaning foods. Additionally, the evidence linking fumonisin exposure to growth impairment in plants and a variety of animal species are reviewed. Finally, we describe interventions to reduce fumonisin in parts of the world where dietary fumonisin exposure is high and is likely to predispose populations to increased health risk.

Environmental Impacts of Abdominal Imaging: A Pilot Investigation

PurposeClinical decision making regarding the use of imaging is appropriately centered on diagnostic efficacy and individual patient factors. However, health policy and imaging guidelines may incorporate other inputs, such as cost-effectiveness and patient preference. In the context of climate change and resource scarcity, the environmental impacts of imaging modalities including ultrasound, CT, and MRI will also become relevant. The purpose of this study was to estimate the environmental impacts of various abdominal imaging examinations. MethodsUsing commercially available software (SimaPro) and data from user manuals and field experts, a streamlined life cycle assessment was performed to estimate multifactorial environmental impacts of the production and use of ultrasound, CT, and MRI per abdominal imaging examination. ResultsUltrasound consumed less energy in both production and use phases (7.8 and 10.3 MJ/examination, respectively) than CT (58.9 and 41.1 MJ/examination) or MRI (93.2 and 216 MJ/examination). Ultrasound emitted fewer CO2 equivalents in production and use phases (0.5 and 0.65 kg/examination) than CT (4.0 and 2.61 kg/examination) or MRI (6.0 and 13.72 kg/examination). Potential human health effects from pollutant emissions were found to be smallest with ultrasound in both production and use phases. ConclusionsAmong the three imaging modalities, ultrasound was found to have the least environmental impact, by one or more orders of magnitude in various domains. This analysis provides an initial framework for comparing environmental impacts across imaging modalities, which may provide useful inputs for cost-effectiveness analyses and policymaking.

Near Real-Time Detection of E. coli in Reclaimed Water.

Advanced treatment of reclaimed water prior to potable reuse normally results in the inactivation of bacterial populations, however, incremental treatment failure can result in bacteria, including pathogens, remaining viable. Therefore, potential microorganisms need to be detected in real-time to preclude potential adverse human health effects. Real-time detection of microbes presents unique problems which are dependent on the water quality of the test water, including parameters such as particulate content and turbidity, and natural organic matter content. In addition, microbes are unusual in that: (i) viability and culturability are not always synonymous; (ii) viability in water can be reduced by osmotic stress; and (iii) bacteria can invoke repair mechanisms in response to UV disinfection resulting in regrowth of bacterial populations. All these issues related to bacteria affect the efficacy of real-time detection for bacteria. Here we evaluate three different sensors suitable for specific water qualities. The sensor A is an on-line, real-time sensor that allows for the continuous monitoring of particulates (including microbial contaminants) using multi-angle-light scattering (MALS) technology. The sensor B is a microbial detection system that uses optical technique, Mie light scattering, for particle sizing and fluorescence emission for viable bacteria detection. The last sensor C was based on adenosine triphosphate (ATP) production. E. coli was used a model organism and out of all tested sensors, we found the sensor C to be the most accurate. It has a great potential as a surrogate parameter for microbial loads in test waters and be useful for process control in treatment trains.

Sources and behavior of perchlorate ions (ClO&amp;lt;sub&amp;gt;4&amp;lt;/sub&amp;gt;&amp;lt;sup&amp;gt;−&amp;lt;/sup&amp;gt;) in chalk aquifer of Champagne-Ardenne, France: preliminary results

Abstract. Perchlorate (ClO4-) is an environmental contaminant of growing concern due to its potential human health effects and widespread occurrence in surface water and groundwater. Analyses carried out in France have highlighted the presence of ClO4- in drinking water of Champagne-Ardenne (NW of France), with two potential sources suspected: a military source related to the First World War and an agricultural source related to the past use of Chilean nitrates. To determine the sources of ClO4- in groundwater, major and trace elements, 2H and 18O, ClO3- and ClO4- ions and a list of 39 explosives were analyzed from 35 surface water and groundwater sampling points in the east of the city of Reims. ClO4- ions were found in almost all sampling points (32 out of 35) with a max value of 33 µg L−1. ClO4- concentrations were highest in groundwater ranging from 0.7 to 33 µg L−1 (average value of about 6.2 µg L−1) against from &lt; 0.5 to 10.2 µg L−1 in surface water (average value of about 2.7 µg L−1). Most of the water samples showing high ClO4- levels (&gt; 4 µg L−1) were collected near a military camp, where huge quantities of ammunitions have been used, stored and destroyed during and after the First World War.

Determination of plasma concentrations of organochlorine pesticides and polychlorinated biphenyls in pet cats and dogs.

The aim of this study was the determination of plasma concentrations of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) in cats and dogs and evaluation of their prevalence and possible effects. The concentrations of nine OCPs, such as α-hexachlorocyclohexane (HCH), β-HCH, γ-HCH, hexachlorobenzene (HCB), aldrin, 2,4'-dichlorodiphenyltrichloroethane (2,4'-DDT), 4,4'-DDT, 2,4'-dichlorodiphenyldichloroethylene (2,4'-DDE) and 4,4'-DDE and 16 PCBs (PCB-28, -52, -70, -74, -81, -99, -101, -118, -138, -153, -156, -170, -180, -183, -187 and -208) were evaluated in the plasma samples of pet cats ( n = 15) and dogs ( n = 21). The concentrations of OCPs ranged from 1.12 ng g-1 lipid weight (lw) to 7.65 ng g-1 lw in cats and from 1.25 ng g-1 lw to 6.79 ng g-1 lw in dogs. In addition, mean PCB levels were 0.58-5.66 and 0.52-6.62 ng g-1 lw in cats and dogs, respectively. β-HCH, γ-HCH and PCB-138 levels were significantly higher in dogs ( p < 0.05). As far as could be determined, OCPs and PCBs were detected in the plasma samples of domestic cats and dogs in Turkey for the first time. Their concentrations were similar to those reported in earlier studies abroad. However, in contrast to other research, the levels of some OCPs were higher in dogs than in cats. It is concluded that, because of their high prevalence and potential health effects in animals and humans, OCP and PCB levels should be monitored systematically in domestic cats and dogs.