Persistent organochlorine pesticide and PCB residues in surface sediments of Lake Qarun,a protected area of Egypt

Organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) were determined in sediment samples collected from 34 locations in Lake Qarun, Egypt to elucidate their concentrations, distribution, possible sources and potential ecological risk. A total of 25 OCPs and 29 PCBs were identified and quantified. OCPs and PCBs were found to be ubiquitous pollutants in the aquatic environment of Lake Qarun, particular near urban areas reflecting the local usage and input of these pollutants. Total concentrations of OCPs and PCBs in sediments ranged from 1.01 to 164.8 ng g^?1 and 1.48 to 137.2 ng g^?1, respectively. Among OCPs, γ-HCH, heptachlor, aldrin, endrin, p,p′-DDE, oxy-chlordane and endosulfan I and II were the most abundant compounds. The composition of PCB congeners was dominated by the tri-, tetra-, penta- and hexa-chlorinated biphenyls. The ratios of certain metabolites (isomers) to their parent compounds (mixtures) indicated there are still new inputs of lindane, endrin, heptachlor and technical endosulfan to Qarun Lake, while the ratios of (p,p′-DDE + p,p′-DDD)/∑p,p′-DDTs indicate earlier usage of DDT. Contamination levels of PCBs and HCHs can be categorized as moderate to high compared to other urbanized regions worldwide. According to established sediment quality guidelines, γ-HCH, endrin and chlordanes would be more concerned OCP species for the ecotoxicological risk in Lake Qarun.     

Concentration of polychlorinated biphenyls and organochlorine pesticides in mullet (Mugil cephalus) and sea bass (Dicentrarchus labrax) from Bizerte Lagoon (Northern Tunisia)

Concentrations of polychlorinated biphenyls (PCBs), and organochlorine pesticides (OCPs) were determined in two fish species, mullet (Mugil cephalus) and sea bass (Dicentrarchus labrax), collected from Bizerte Lagoon and the Mediterranean Sea. In all samples, PCBs were found in higher concentrations than OCPs. The highest concentrations of OCPs and PCBs were found in sea bass, and in Bizerte Lagoon. Concentrations of DDTs and PCBs detected in this study were generally comparable or slightly higher than those found in studies from other Mediterranean and non-Mediterranean regions subject to a high anthropogenic impact. ∑PCBs, ∑HCHs and HCB levels were negatively correlated with lipid content, while no such correlation was seen for ∑DDTs. A significant correlation between levels and length and between levels and weight existed only for ∑PCBs. The daily intake of PCBs and OCPs ingested by people living in Bizerte through the studied fish species was estimated and compared with those observed in other areas.     

Brown rust disease control in winter wheat: II. Exploring the optimization of fungicide sprays through a decision support system

A decision support system (DSS) involving an approach for predicting wheat leaf rust (WLR) infection and progress based on night weather variables (i.e., air temperature, relative humidity, and rainfall) and a mechanistic model for leaf emergence and development simulation (i.e., PROCULTURE) was tested in order to schedule fungicide time spray for controlling leaf rust progress in wheat fields. Experiments including a single fungicide treatment based upon the DSS along with double and triple treatment were carried out over the 2007–2009 cropping seasons in four representative Luxembourgish wheat field locations. The study showed that the WLR occurrences and severities differed according to the site, cultivar, and year. We also found out that the single fungicide treatment based on the DSS allowed a good protection of the three upper leaves of susceptible cultivars in fields with predominant WLR occurrences. The harvested grain yield was not significantly different from that of the double and triple fungicide-treated plots (P?<?0.05). Such results could serve as basis or be coupled to cost-effective and environmentally friendly crop management systems in operational context.     

Assessment of genotoxic effects of lead in occupationally exposed workers

The genotoxicological effects in 200 lead acid storage battery recycling and manufacturing industry workers in Hyderabad along with matched 200 controls were studied. The genetic damage was determined by comet, micronucleus (MN), and chromosomal aberration (CA) test in peripheral blood lymphocytes (PBL). The MN test was also carried out in buccal epithelial cells (BECs). Pb in ambient air, blood Pb (B-Pb) concentrations, and hematological parameters were measured. The superoxide dismutase (SOD), catalase (CAT), glutathione (GSH), glutathione peroxidase (GPx), and malondialdehyde (MDA) formed were also studied. The results of the present study showed that there was a statistically significant (P?P?GPx, and CAT levels were significantly decreased while GSH and MDA levels increased in exposed group when compared to control group. The present study suggests that environmental health standards should be enforced to control Pb contamination from battery industries to reduce human health risk.     

Impact of an educational program on knowledge and practice of health care staff toward pharmaceutical waste management in Gaza,Palestine

In health care facilities, pharmaceutical waste is generally discharged down the drain or sent to landfill. Poor knowledge about their potential downstream impacts may be a primary factor for improper disposal behavior. The objective of this study was to determine the impact of an intervention program on knowledge and practice of health care staff regarding pharmaceutical waste management. The study was designed as a pre/posttest intervention study. Total sample size was 530 in the pre-intervention phase, and then a subsample of 69 individuals was selected for the intervention and the post-intervention phases. Paired-sample t test was used to assess the difference between pretest and follow-up test results. A statistically significant improvement in knowledge and practice was achieved (P < 0.001). Poor knowledge and poor practice levels (scores <50%) were found to improve to satisfactory levels (scores ≥75%). Therefore, educational programs could be considered as an effective tool for changing health care staff practice in pharmaceutical waste management.

Implications: In health care facilities, pharmaceutical waste is generally discharged down the drain or sent to landfill. A lack of knowledge about the potential impacts of this type of waste may be a leading factor in improper disposal behavior. Following an educational program, statistically significant improvement in knowledge and practice of health care staff as regards to pharmaceutical waste management (PWM) was achieved. It is thus recommended that authorities implement training-of-trainers (TOT) programs to educate health care staff on PWM and organize refreshment workshops regularly.     

Eco-material selection using fuzzy TOPSIS method

In the classical multiple attribute decision-making or MADM methods, the ratings and the weights of the criteria are known precisely. However, in eco-material selection exercises, the available data are typically inadequate because of the selection dual quantitative and qualitative natures. Some of the qualitative selection criteria can be rated in several classes rather being expressed by exact numerical values; hence the application of fuzzy concepts in decision-making seems attractive to deal with such kind of ratings. Thusly, the presented study attempts to propose an eco-material selection approach specific to the automobile body panels using a fuzzy technique for order preference by similarity to ideal solution (TOPSIS), to incorporate both numerical and rating-based criteria into one holistic sustainability model. TOPSIS and fuzzy logic can aid the material selection process in translating the design goals and parameters into usable numbers that in turn can be used to rank candidate materials in their closeness to the ideal solution. An additional uniqueness of this study stems from using the fuzzy-TOPSIS as a scoring tool without any assigned weights for the different selection attributes, in order to avoid the bias that is typically associated with other classical MADM, such as quality function deployment, analytical hierarchy process and digital logic.     

Seasonal variations in cholinesterase activity, nerve conduction velocity and lung function among sprayers exposed to mixture of pesticides

Pesticide spraying operation is associated with the increased risk of adverse health effects among sprayers who do not follow safe farm work practices. A study was conducted among pesticide sprayers in North India to evaluate the clinical and subclinical variations in their vital health parameters before and after the pesticide spraying season. Blood cholinesterase levels, pulmonary function test, nerve conduction velocity and self-reported symptoms were studied among 18 eligible and consenting male sprayers. Mean acetylcholinesterase activity was reduced by 55 % in the post-exposure assessment (P?<?0.001) as compared to pre-exposure levels. Mean forced expiratory volume in 1 s was 20 % lower in the post-exposure assessment as compared to the pre-exposure level (P?<?0.05). No significant change was observed in the motor and sensory nerve conduction velocity in the median nerve of sprayers before and after the spraying activity. Also, no significant variation was observed with respect to self-reported symptoms except weakness in arms and legs (P?<?0.05). The significant decline in lung function and acetylcholinesterase level after pesticide exposure reflects the strongly negative effect of exposure to pesticides during spraying activity. More longitudinal studies among pesticide sprayers must be undertaken to further substantiate the cause–effect relationship between pesticide exposure and its subclinical effects. There is a strong necessity to minimise the exposure through the use of personal protective equipment in pesticide sprayers.     

Delayed neurotoxicity of cyanofenphos in chickens

Abstract

Delayed neurotoxic ataxia, similar to that caused by neurotoxic organophosphorous compounds, has been shown to occur in hens after oral administration of Cyanofenphos (O‐ethyl‐O‐Cyanophenyl phenyl phosphonothionate) following either single or repeated oral doses. Axonal and myelin degeneration affecting the long tracts in spinal cord, peripheral nerves and medulla was demonstrated. The distal fibers with large diameters were particularly affected. This finding is a new contribution which has not been previously recorded. It implies that a thorough study of the structure‐activity relationships of phosphonothionates regarding their delayed neurotoxic effect is warranted.     

Numerical study on the spontaneous ignition of pressurized hydrogen release through a tube into air

Spontaneous ignition of pressurized hydrogen release through a tube into air is investigated using a modified version of the KIVA-3V CFD code. A mixture-averaged multi-component approach is used for accurate calculation of molecular transport. Autoignition and combustion chemistry is accounted for using a 21 step kinetic scheme. Ultra fine meshes are employed along with the Arbitrary Lagrangia–Eulerian (ALE) method to reduce false numerical diffusion. The study has demonstrated a possible mechanism for spontaneous ignition through molecular diffusion.

In the simulated scenario, the tube provided additional time to achieve a combustible mixture at the hydrogen–air contact surface. When the tube was sufficiently long under certain release pressure, autoignition would initiate inside the tube at the contact surface due to mass and energy exchange between low temperature hydrogen and shock-heated air through molecular diffusion. Following further development of the hydrogen jet downstream, the contact surface became distorted. Turbulence plays an important role for hydrogen/air mixing in the immediate vicinity of this distorted contact surface and led the initial laminar flame to transit into a stable turbulent flame.     

Total and Leachable Heavy Metals in Muddy and Sandy Sediments of Egyptian Coast Along Mediterranean Sea

The assessment of marine pollution due to metals was made for surficial sediments sampled from 20 sites along Mediterranean coast of Egypt. The samples were dried, acid digested and analyzed for leachable and total heavy metal contents (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) by flame atomic absorption spectrophotometer (air–acetylene) with deuterium background correction. Evaluation of the heavy metals pollution status was carried out using enrichment factors (EFs), the effect range-low (ERL) and the effect range-median (ERM). The study showed high concentrations of Cd, Co, Pb, Ni and moderate concentrations of Cr, Cu and Mn were contaminated in the sediments of studied sites. The results of Spearman correlation, factor and cluster analysis of the heavy metals analyzed in the collected sediment were discussed. The main source of contamination is the offshore oil field and industrial wastes, which arise due to the ineffective and inefficient operation equipments, illegal discharge and lack of supervision and prosecution of offenders.