Feasibility of using low density polyethylene sheets to detect atmospheric organochlorine pesticides in Alexandria, Egypt

Egypt is a major agricultural country in Africa with a known past of organochlorine pesticides (OCPs) application, yet data on atmospheric levels of OCPs in Egypt is sparse. Low density polyethylene (LDPE) passive samplers were therefore deployed for 3 weeks each at 11 locations in July, 2010 and January, 2011 in Alexandria to screen for gas-phase OCPs. Performance reference compounds were used to investigate the uptake kinetics. Field-derived sampler-air partitioning coefficients (KPE-As) for OCPs were significantly correlated against the compounds\u27 subcooled liquid vapor pressure (log PL): [log KPE-A = −0.77 ± 0.07*log PL + 6.35 ± 0.13 (R2 = 0.90; n = 17; SE = 0.19; p \u3c 0.001)]. Estimated and measured OCP concentrations in Alexandria agreed well (factor difference ≤ 2) indicating the feasibility of monitoring OCPs using LDPEs. OCP concentrations ranged from 3. Calculated isomeric ratios indicated recent usage of chlordanes and endosulfans

Using Polyethylene Passive Samplers to Study the Partitioning and Fluxes of PBDEs in an Urban River

In the aquatic environment, the behavior of hydrophobic organic contaminants (HOCs), such as polybrominated diphenyl ethers (PBDEs), depends on the congeners’ physicochemical properties, environmental conditions and the presence of competing natural sorbents, including particulate and dissolved organic carbon (DOC) and black carbon (BC). Although BC is known as an important sedimentary sorbent for HOCs, its affinity for PBDEs has been poorly constrained. To better understand the biogeochemical controls on PBDEs, 12 PBDE congeners were measured in air, water, sediment and porewater of the lower Passaic River. BDE-47 and BDE-99 dominated in all media. In sediments and water, the dual OC + BC approach better predicted PBDE partitioning compared to the simple OC isotherm. Field-derived KBC for PBDEs were inverse correlated with aqueous solubility [log KBC sediments (water) = -log Cwsat * 0.95 (1.2) + 0.36 (-0.69)]; they reflected near background to highly contamination regions across the Passaic River. In the water column, PBDEs appeared at equilibrium partitioning between particles and colloids: OC + BC were responsible for the sorption of 65 % of the concentrations of PBDE, followed by colloids (30%); only 5 % of PDBEs were truly dissolved. Calculated sediment-water diffusive fluxes greatly overwhelmed the atmospheric depositional flux to the river

Source Apportionment and Risk Assessment of Polycyclic Aromatic Hydrocarbons in the Atmospheric Environment of Alexandria, Egypt

In this study, three receptor models [factor analysis/multiple linear regression (FA/MLR), positive matrix factorization (PMF) and UNMIX] were applied seasonally to investigate the source apportionment of PAHs in the atmospheric environment of Alexandria, and a lifetime cancer risk was assessed. ∑44 (gas+particle) PAH concentrations varied from 330 to 1770ngm(-3) and 170-1290ngm(-3) in the summer and winter seasons respectively. PAH concentrations at the industrial sites were significantly higher than at the traffic and residential sites during the winter season (

Assessing benthic bioaccumulation of polychlorinated dioxins/furans (PCDD/Fs) and polychlorinated biphenyls (PCBs) in the lower Passaic River (NJ, USA) based on \u3cem\u3ein situ\u3c/em\u3e passive sampling

Passive sampling has emerged as a promising tool to assess the presence of hydrophobic organic contaminants (HOC) in water, sediment and biota, such as polychlorinated dibenzo‐p‐dioxins/furans (PCDD/Fs) or polychlorinated biphenyls (PCBs). Previous work evaluated the ability of passive samplers to predict bioavailability of sedimentary HOCs mostly in the laboratory, often for marine organisms. The current study assessed the use of low density polyethylene (LDPE) to derive freely dissolved concentrations of PCDD/Fs and PCBs in porewater in situ versus ex situ , and in river water. A LDPE‐based multisampler system was deployed at four locations along the lower Passaic River (NJ) in sediment and water column, where sediment and benthic species samples were also collected. Good agreement was generally observed for PCDD/F and PCB concentrations comparing in situ and ex situ approaches (within 0.30 – 39%). Significant linear relationships were derived between log LDPE based – log lipid‐based concentrations of PCDD/Fs and PCBs. The in situ multisampler system showed promise to derive HOC concentrations in porewater and riverwater, and to predict the bioaccumulation potential of HOCs in benthic biota

Uptake of hydrophobic organic compounds, including OCPs and PBDEs, and perfluoroalkyl acids (PFAAs) in fish and blue crabs of the lower Passaic River (NJ, USA)

The bioavailability and bioaccumulation of sedimentary hydrophobic organic compounds (HOCs) is of concern at contaminated sites. Passive samplers have emerged as a promising tool to measure the bioavailability of sedimentary HOCs and possibly to estimate their bioaccumulation. We thus analyzed HOCs including organochlorine pesticides (OCPs), polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs) and polychlorinated dibenzo‐p‐dioxins/furans (PCDD/Fs) in sediment, porewater and riverwater using low density polyethylene (LDPE) passive samplers, and in 11 different finfish species and blue crab from the lower Passaic River. Additionally, perfluorinated alkyl acids (PFAAs) were measured in grab water samples, sediment and fish. Best predictors of bioaccumulation in biota were either porewater concentrations (for PCBs and OCPs), or sediment organic carbon (PBDEs and PFAAs), including black carbon (OCPs, PCBs and some PCDD/F congeners) normalized concentrations. Measured lipid‐based concentrations of the majority of HOCs exceeded the chemicals\u27 activites in porewater by at least 2‐fold, suggesting dietary uptake. Trophic magnification factors were \u3e 1 for moderately hydrophobic analytes (log KOW = 6.5–8.2) with low metabolic transformation rates (\u3c 0.01 day−1), including longer alkyl chain PFAAs. For analytes with lower (4.5–6.5) and higher (\u3e8.2) KOWs, metabolic transformation was more important in reducing trophic magnification

Significance of Population Centers As Sources of Gaseous and Dissolved PAHs in the Lower Great Lakes

Polyethylene passive samplers (PEs) were used to measure concentrations of gaseous and dissolved polycyclic aromatic hydrocarbons (PAHs) in the air and water throughout the lower Great Lakesduring summer and fall of 2011. Atmospheric Σ15PAH­ concentrations ranged from 2.1 ng/m3 in Cape Vincent (NY) to 76.4 ng/m3 in downtown Cleveland (OH). Aqueous Σ18PAH concentrations ranged from 2.4 ng/L at an offshoreLake Erie site to 30.4 ng/L in Sheffield Lake (OH). Gaseous PAH concentrations correlated strongly with population within 3-40 km of the sampling site depending on the compound considered, suggesting that urban centers are a primary source of gaseous PAHs (except retene) in the lowerGreat Lakes region. The significance of distant population (within 20 km) versus local population (within 3 km) increased with sub-cooled liquid vapor pressure. Most dissolved aqueous PAHs did not correlate significantly with population, nor were they consistently related to river discharge, wastewater effluents, or precipitation. Air-water exchange calculations implied that diffusive exchange was a source of phenanthrene to surface waters, while acenaphthylene volatilized out of the lakes. Comparison of air-water fluxes with temperature suggested that the significance of urban centers as sources of dissolved PAHs via diffusive exchange may decrease in warmer months

Estimation of Uncertainty in Air-­Water Exchange Flux 2 and Gross Volatilization Loss of PCBs: a Case Study 3 based on Passive Sampling in the Lower Great Lakes

Compared with dry and wet deposition fluxes, air–water exchange flux cannot be directly measured experimentally. Its model-based calculation contains considerable uncertainty because of the uncertainties in input parameters. To capture the inherent variability of air–water exchange flux of PCBs across the lower Great Lakes and to calculate their annual gross volatilization loss, 57 pairs of air and water samples from 19 sites across Lakes Erie and Ontario were collected using passive sampling technology during 2011–2012. Error propagation analysis and Monte Carlo simulation were applied to estimate uncertainty in the air–water exchange fluxes. Results from both methods were similar, but error propagation analysis estimated a smaller uncertainty than Monte Carlo simulation in cases of net deposition. Maximum likelihood estimations (MLE) of wind speed and air temperature were recommended to quantify the site-specific air–water exchange flux. An assumed 30–40% of relative uncertainty in overall air–water mass transfer velocity was confirmed. MLEs of volatilization fluxes of total PCBs across Lakes Erie and Ontario were 0.78 and 0.53 ng m–2 day–1, respectively, and gross volatilization losses of total PCBs over the whole lakes were 74 kg year–1 for Lake Erie and 63 kg year–1 for Lake Ontario. Mass balance analysis across Lake Ontario indicated that volatilization was the uppermost loss process of aqueous PCBs

Use of Foley\u27s catheter balloon tamponade to control placental site bleeding resulting from major placenta previa during cesarean section

Aim: To evaluate the effect of 2-way Foley\u27s catheter balloon tamponade on controlling immediate postpartum hemorrhage (PPH) in cases of major placenta previa during cesarean section (CS). Methods: We evaluated women with placenta previa from May to November 2015. Women with immediate PPH during CS due to major placenta previa were managed by 2-way Foley\u27s catheter balloon tamponade when medical treatment failed, and before any surgical intervention. Results: Twenty patients, had major placenta previa, were delivered by elective CS and complicated by immediate PPH. Three placenta accreta patients (15%) underwent hysterectomy, 17 (85%) were managed by the 2-way Foley\u27s catheter balloon tamponade. In two patients, Foley\u27s catheter balloon failed to control bleeding and hysterectomy was done immediately. However, Foley\u27s catheter balloon successfully treated the remaining 15 patients. The median bleeding during the operation was 1522.5 (± 619.29) ml. None of them presented complications related to this procedure or required any further invasive surgery. Conclusion: The 2-way Foley\u27s catheter tamponade could be an option to control immediate postpartum hemorrhage resulting from major placenta previa during the cesarean section. This method is simple, cheap, nearly non-invasive and should be considered to reduce the risk of peripartum hysterectomy

Insulin sensitizing agent improves clinical pregnancy rate and insulin resistant parameters in polycystic ovarian syndrome patients with acanthosis nigricans: a randomized controlled study

Objective: To investigate the effect of adding metformin to clomiphene citrate (CC) in polycystic ovarian syndrome (PCOS) patients with acanthosis nigricans (AN) who were previously not responding to CC. Material and Methods: A double blinded randomized controlled trial (NCT02562664) included 66 PCOS women with acanthosis nigricans who were CC resistant (at least 3 months). Day 3 follicle stimulating hormone (FSH) level, fasting insulin, fasting glucose and homeostatic model assessment were used to quantify insulin resistance. Participants were randomly assigned to either group I (CC with placebo tablets) or group II (CC with metformin) for three cycles. Insulin resistance parameters as well as clinical pregnancy rate had been evaluated in both groups. The statistical analysis was done using Chi- square and Fischer exact tests. Results: The demographic data was comparable in both groups, however; there was higher cumulative pregnancy rate after three cycles of stimulation in group II (18/33) (54.5%) in comparison with group I (7/33) (21.1%) (P=0.03). There was a significant improvement in the insulin resistance parameters after three months of combining clomiphene citrate with metformin as compared with CC alone. Conclusion: Adding metformin to CC in clomiphene citrate resistant PCOS patients who have acanthosis nigricans improves the pregnancy rate and insulin resistant parameters

Pharmacodynamic and Pharmacokinetic Studies on Tetracycline Hydrochloride in Rabbits

Tetracycline is one of the most important groups of antibiotics that have harmful effects on the consumers, therefore the public health safety against its residues represents a significant issue. This study aimed to estimate the effect of tetracycline hydrochloride on some hematological parameters, kidneys function tests as well as liver and breast muscle enzymes with special reference to the supposed withdrawal time of this drug in different rabbits’ tissues (kidney, liver and muscles), following oral dose of tetracycline using High Performance Liquid Chromatography. Tetracycline was administrated to eighteen rabbits directly into the stomach at a dose of 35 mg/kg BW once daily for five successive days. Samples were collected on the 1st, 3rd, 7th, 14th, 21st and 28th days after the last oral dose. The results revealed that, tetracycline caused a significant increase in the uric acid, urea, creatinine, alkaline phosphatase (ALP), aspartate aminotransferase (AST), alanine aminotransferase (ALT), creatine phosphokinase (CPK) and lactate dehydrogenase (LDH) activities with no significant changes in the hematological parameters when compared with the control group. The residues remained in the liver and kidney for 7 days, while in muscles for 3 days only after the last oral dose of the drug. In conclusion, the disturbances in the biological parameters occurred by tetracycline administration in rabbits was transient and returned to normal after 7 days of last treatment. The withdrawal time of tetracycline was 14 days from the rabbit's tissues