Application of 96-well plate SPE method for analysis of persistent organic pollutants in low volume blood serum samples

Though many persistent organic pollutants (POPs) are closely regulated the human population is still exposed to these ubiquitous chemicals from the environment and diet. Safe management and human biomonitoring of POPs is necessary to understand the risk of exposure. Within human biomonitoring the mass of sample is often limited, therefore robust methods using smaller sample amounts are necessary. This study developed a 96-well plate solid phase extraction (SPE) method for determination of selected POPs: polychlorinated biphenyls (PCBs), organo-chlorine pesticides (OCPs), polybrominated diphenyl ethers (PBDEs), hexabromocyclododecane (HBCD) and non-persistent novel flame retardants (NFRs) in low volume blood serum. Non-destructive clean-up coupling Oasis HLB extraction plate with Phree phospholipid removal plate was employed. Extraction efficiency was determined at low and high concentrations in certified reference materials NIST SRM 1957 and 1958, respec-tively. Target compounds deviated from certified values on average by 15% and 21% for SRM 1957 and SRM 1958, respectively. Observed limit of detections (LODs) ranged from 0.36 pg/mL (PCB 180) to 66.07 pg/mL (delta-HCH). The applicability for real samples is demonstrated on 48 samples from pregnant women enrolled in the pilot phase of the CELSPAC: TNG study. In total, 30 target compounds were detected in at least one sample. The method developed here provides a fast and reliable analysis of human blood serum with possibility to introduce automation for the sample preparation procedure

Accumulation of perfluoroalkyl compounds in Tibetan mountain snow:temporal patterns from 1980 to 2010

The use of snow and ice cores as recorders of environmental contamination is particularly relevant for per- and polyfluoroalky substances (PFASs) given their production history, differing source regions and varied mechanisms driving their global distribution. In a unique study perfluoroalkyl acids (PFAAs) were analyzed in dated snow-cores obtained from high mountain glaciers on the Tibetan Plateau (TP). One snow core was obtained from the Mt Muztagata glacier (accumulation period of 1980–1999), located in western Tibet and a second core from Mt. Zuoqiupo (accumulation period: 1996–2007) located in southeastern Tibet, with fresh surface snow collected near Lake Namco in 2010 (southern Tibet). The higher concentrations of ∑PFAAs were observed in the older Mt Muztagata core and dominated by perfluorooctanesulfonic acid (PFOS) (61.4–346 pg/L) and perfluorooctanoic acid (PFOA) (40.8–243 pg/L), whereas in the Mt Zuoqiupu core the concentrations were lower (e.g., PFOA: 37.8–183 pg/L) with PFOS below detection limits. These differences in PFAA concentrations and composition profile likely reflect the upwind sources affecting the respective sites (e.g., European/central Asian sources for Mt Muztagata and India sources for Mt Zuoqiupu). Perfluorobutanoic acid (PFBA) dominated the recent surface snowpack of Lake Namco which is mainly associated with India sources where the shorter chain volatile PFASs precursors predominate. The use of snow cores in different parts of Tibet provides useful recorders to examine the influence of different PFASs source regions and reflect changing PFAS production/use in the Northern Hemisphere

Oxygenated and Nitrated Polycyclic Aromatic Hydrocarbons in Ambient Air-Levels, Phase Partitioning, Mass Size Distributions, and Inhalation Bioaccessibility

Among the nitrated and oxygenated polycyclic aromatic hydrocarbons (NPAHs and OPAHs) are some of the most hazardous substances to public health, mainly because of their carcinogenicity and oxidative potential. Despite these concerns, the concentrations and fate of NPAHs and OPAHs in the atmospheric environment are largely unknown. Ambient air concentrations of 18 NPAHs, 5 quinones, and 5 other OPAHs were determined at two urban and one regional background sites in central Europe. At one of the urban sites, the total (gas and particulate) concentrations of Sigma(10)OPAHs were 10.0 +/- 9.2 ng/m(3) in winter and 3.5 +/- 1.6 ng/m(3) in summer. The gradient to the regional background site exceeded 1 order of magnitude. Sigma(18)NPAH concentrations were typically 1 order of magnitude lower than OPAHs. Among OPAHs, 9-fluorenone and (9,10)-anthraquinone were the most abundant species, accompanied by benzanthrone in winter. (9,10)-Anthraquinone represented two-thirds of quinones. We found that a large fraction of the target substance particulate mass was carried by submicrometer particles. The derived inhalation bioaccessibility in the PM10 size fraction is found to be approximate to 5% of the total ambient concentration of OPAHs and up to approximate to 2% for NPAHs. For 9-fluorenone and (9,10)-anthraquinone, up to 86 and 18%, respectively, were found at the rural site. Our results indicate that water solubility could function as a limiting factor for bioaccessibility of inhaled particulate NPAHs and OPAHs, without considerable effect of surfactant lipids and proteins in the lung lining fluid

THE UPTAKE OF TRITIUM ONTO SEDIMENTS IN AQUATIC SYSTEMS

The refuelling and refitting of submarines in the Tamar Estuary causes the disposal of low-level liquid waste into the lower estuary. This contains up to 800 gigabecquerels (G8q) of tritium per year plus an additional aerial discharge of gaseous tritium is released. The actual level of tritiated water disposed per refuelling is in itself not documented. The aim of this project was twofold firstly to quantify the concentration of tritium in the sediments through analysis of pore water, the electrostatically bound fraction and the sediment bound fraction. This was to assess the levels already available. The second stage was to quantify the potential uptake available within the system if tritium disposal continues. Overall there is a large discrepancy between sites assessed in the Tamar. This can be justified by the geographic location and water flow at sites but does indicate a difference in an order of magnitude from sites just 0.2 Km apart. The volumes in the sediment are ten times greater than that either electrostatically bound or in the pore water. The dosing experiments gave low K! for tritium using coarse bed sediments however there was significantly measurable uptake, and the maximal volume capable of being taken up onto sediments has not been reached, within the current environmental levels. The future for the study of the uptake should be to quantify the maximal uptake possible per unit volume and to quantify the volume to be re-released based on a gradient of tritium for understanding of future bed sediment source for the estuary.Faculty of Scienc

Polyfluoroalkyl compounds in the Canadian Arctic atmosphere

Polyfluoroalkyl compounds (PFCs) were determined in high-volume air samples during a ship cruise onboard the Canadian Coast Guard Ship Amundsen crossing the Labrador Sea, Hudson Bay and the Beaufort Sea of the Canadian Arctic. Five PFC classes (i.e. perfluoroalkyl carboxylates (PFCAs), polyfluoroalkyl sulfonates (PFSAs), fluorotelomer alcohols (FTOHs), fluorinated sulfonamides (FOSAs), and sulfonamidoethanols (FOSEs)) were analysed separately in the gas phase collected on PUF/XAD-2 sandwiches and in the particle phase on glass-fibre filters (GFFs). The method performance of sampling, extraction and instrumental analysis were compared between two research groups. The FTOHs were the dominant PFCs in the gas phase (20-138 pg m(-3)), followed by the FOSEs (0.4-23 pg m(-3)) and FOSAs (0.5-4.7 pg m(-3)). The PFCAs could only be quantified in the particle phase with low levels ( FOSAs (similar to 9%) > FTOHs (similar to 1%). Significant positive correlation between Sigma FOSA concentrations in the gas phase and ambient air temperature indicate that cold Arctic surfaces, such as the sea-ice snowpack and surface seawater could be influencing FOSAs in the atmosphere

Human dietary intake and hazard characterization for residues of neonicotinoides and organophosphorus pesticides in Egyptian honey

<p>In two recently published reports, hazards posed by dietary exposure to organophosphate and neonicotinoid plant protection products on the European honey bee (<i>Apis mellifera</i> L.) in Egypt were investigated. Using concentrations reported in those studies, an assessment of hazards posed by these two classes of insecticides to humans due to consumption of Egyptian honey from the Nile Delta during both spring and summer was performed. Twenty-eight compounds including metabolites were assessed for exposure of adult Egyptians based on the best- and worst-case scenarios. Even for the worst-case scenario, exposure to these two classes of pesticides in honey was 15-fold less than hazard index value of 1.0 for adverse effects on humans. Based upon this analysis, people exposed to these insecticides through consumption of honey products would be unlikely to exhibit adverse health outcomes.</p

The fate of per- and polyfluoroalkyl substances within a melting snowpack of a boreal forest

Per- and polyfluoroallcyl substances (PFAS) were measured systematically in a snowpack in northern Sweden to determine chemical behaviour during seasonal melt. Average PFAS concentrations were generally low, but displayed a wide range with median (range) concentrations of PFOA and PFOS of 66.5 pg L-1 (ND-122) and 20.5 pg L-1 (2.60-253) respectively. Average concentrations of the shorter chain, C4 and C5 perfluoroalkyl carboxylates (PFCAs) and perfluoroalkyl sulfonates (PFSAs), were similar to 10-fold higher. Differences in the PFAS concentrations and profile were observed between surface snow and deeper layers, with evidence of PFAS migration to deeper snow layers as melt progressed. Chemical loads (ng m(-2)) for C4-9 PFCAs decreased gradually as melt progressed, but increased for C-4, C6-8 PFSAs and the longer chain C10-12 PFCAs. This enrichment in the diminishing snowpack is an unusual phenomenon that will affect PFAS elution with meltwater and subsequent entry to catchment surface waters. (C) 2014 Elsevier Ltd. All rights reserved

Exposure of honeybees (Apis mellifera) in Saskatchewan, Canada to organophosphorus insecticides

International audienceConcentrations of 14 organophosphorus insecticides (OPs) were measured in Apis mellifera L. (European honeybee) and hive matrices (honey and bee bread). Samples were collected from seven randomly selected colonies in central Saskatchewan during the summer of 2013. LC-MS/MS was used to identify and quantify individual OP by use of a modified quick easy cheap effective rugged safe (QuEChERS) method. Diazinon, dimethoate, and chlorpyrifos-oxon were the only OPs detected in honey with mean concentrations of 0.3, 1.5, and 0.2 ng/g, wet mass (wm), respectively. Fenamiphos, chlorpyrifos, and chlorpyrifos methyl were the only OPs detected in bee bread, with mean concentrations of 0.4, 2.7, and 15.8 ng/g, wm, respectively, while ethoprop, malathion, and dichlorvos were the only OPs detected in bees with mean concentrations of 1.4, 3.7, and 889.2 ng/g, wm, respectively. Total hazard quotients (HQs), based on lethality of bees exposed to OPs in honey and pollen consumed by bees ranged from 0.01 to 0.06 and based on lethality of bees from direct exposure to OPs ranged from 0.3 to 0.4 which suggests little hazard of OPs to Saskatchewan beehives

Hidrocarburos aromáticos policíclicos (HAP) en leche materna humana de Colombia: ocurrencia espacial, fuentes y evaluación probabilística de riesgo

8 páginasThe diet is the main route that polycyclic aromatic hydrocarbons (PAHs) enter the body and measuring breast milk is one of the best ways to understand the maternal body burden and can be passed on to infants. In this study, it was determinate the concentrations of 23 PAHs in 60 milk samples taken from 3 cities in Colombia and to determine the potential routes of exposure and risk to human health. On average, concentration for the ∑PAHs across all locations was 186.6 ng g−1, lipid mass (LM), with city means of 260.1, 175.7, and 123.9 ng g−1 LM for Cartagena, Bogota and Medellin, respectively. Monte Carlo simulations were used to estimate the hazard quotient (HQ) and incremental lifetime cancer risk (ILCR) for infant dietary exposure to PAHs. HQs were below the safe thresholds (HQ = 1) while ILCRs were greater than the reference value equal to 10−6 (mg kg−1day−1). Dietary source assessment indicated that fish is a significant source of PAHs, with mothers that consumed fish at least once per week having ∼2.5 times greater PAH milk concentrations than other groups. While a disparity was also observed among consumers of exclusively marine (∑PAHs 198.5 ng g−1 LM) or freshwater fish (∑PAHs 85.7 ng g−1 LM). However, geographical considerations can be significant in this finding.La dieta es la ruta principal por la que los hidrocarburos aromáticos policíclicos (HAP) ingresan al cuerpo y medir la leche materna es una de las mejores formas de comprender la carga corporal materna y puede transmitirse a los bebés. En este estudio se determinaron las concentraciones de 23 PAHs en 60 muestras de leche tomadas de 3 ciudades de Colombia y determinar las posibles vías de exposición y riesgo para la salud humana. En promedio, la concentración de ∑PAH en todas las ubicaciones fue de 186,6 ng g−1, masa lipídica (LM), con medias de ciudad de 260,1, 175,7 y 123,9 ng g−1 LM para Cartagena, Bogotá y Medellín, respectivamente. Se utilizaron simulaciones de Monte Carlo para estimar el cociente de riesgo (HQ) y el riesgo incremental de cáncer a lo largo de la vida (ILCR) para la exposición dietética infantil a HAP. Los HQ estaban por debajo de los umbrales de seguridad (HQ = 1) mientras que los ILCR estaban por encima del valor de referencia igual a 10−6 (mg kg−1día−1). La evaluación de la fuente dietética indicó que el pescado es una fuente importante de HAP, y las madres que consumían pescado al menos una vez por semana tenían concentraciones de PAH en la leche ~2,5 veces mayores que otros grupos. Mientras que también se observó una disparidad entre los consumidores de pescado exclusivamente marino (∑PAHs 198,5 ng g−1 LM) o de agua dulce (∑PAHs 85,7 ng g−1 LM). Sin embargo, las consideraciones geográficas pueden ser significativas en este hallazgo