Urinary dialkyl phosphate levels before and after first season chlorpyrifos spraying amongst farm workers in the Western Cape, South Africa

The study investigated urinary levels of dialkyl phosphates resulting from pesticide exposure amongst 40 farm workers. Workers were tested (urinary dialkyl phosphate levels, anthropometry, short exposure questionnaire) before and after the first day of seasonal chlorpyrifos spraying. Median baseline urinary dialkyl phosphates was high amongst both non-applicators (1587.5 μg/g creatinine, n = 8) and applicators (365.6 μg/g creatinine, n = 9). There was not much evidence of an increase in post-spray dialkyl phosphates levels from pre-spray levels amongst both applicators and non-applicators. Hours mixing, spraying, driving a tractor and hours worked by non-applicators were not significantly associated with an increase in post-spray dialkyl phosphate levels, adjusting for age, height, weight, gender, use of empty pesticide containers and self-reported kidney problems. Past applicator status was weakly positively associated with pre-spray dialkyl phosphate levels adjusting for age, height, weight, and gender, self-reported kidney problems, smoking and alcohol (β= 1019.5, p = 0.307, R2 = 0.28). The high dialkyl phosphate levels call for an epidemiological investigation into the health effects of organophosphorous pesticides.     

Stochastic analysis of concentration field in a wake region

Introduction  

Identifying geographic locations in urban areas from which air pollutants enter the atmosphere is one of the most important information needed to develop effective mitigation strategies for pollution control.     

National culture and safe work behaviour of construction workers in Pakistan

It is widely accepted that unsafe behaviour is intrinsically linked to workplace accidents. A positive correlation exists between workers’ safe behaviour and safety climate on construction sites. Construction workers’ attitude towards safety is influenced by their perception of risk, management, safety rules and procedures. Pakistan, a developing country, is currently experiencing a strong growth in its construction activities. Unfortunately, the enforcement of safety regulations in Pakistan is not widespread. Indeed, some relevant regulations are both outdated and irrelevant to daily construction operations. This paper investigates local construction workers’ behaviour, perception and attitude toward safety, and attempts to link the research findings to the influence of national culture. A three-part interview-based questionnaire survey has identified that the majority of workers have a good degree of risk awareness and self-rated competence. Additionally, workers’ intentional behaviour was empirically explained by their attitudes towards their own and management’s safety responsibilities, as well as their perception of the risk they are generally exposed to in their workplace. The paper also reveals that workers operating in a more collective and higher uncertainty avoidance environment, are more likely to have safety awareness and beliefs, which can exhibit safer on-site behaviour.     

Estimating the effect of nitrogen fertilizer on the greenhouse gas balance of soils in Wales under current and future climate

The Welsh Government is committed to reduce greenhouse gas (GHG) emissions from agricultural systems and combat the effects of future climate change. In this study, the ECOSSE model was applied spatially to estimate GHG and soil organic carbon (SOC) fluxes from three major land uses (grass, arable and forest) in Wales. The aims of the simulations were: (1) to estimate the annual net GHG balance for Wales; (2) to investigate the efficiency of the reduced nitrogen (N) fertilizer goal of the sustainable land management scheme (Glastir), through which the Welsh Government offers financial support to farmers and land managers on GHG flux reduction; and (3) to investigate the effects of future climate change on the emissions of GHG and plant net primary production (NPP). Three climate scenarios were studied: baseline (1961–1990) and low and high emission climate scenarios (2015–2050). Results reveal that grassland and cropland are the major nitrous oxide (N₂O) emitters and consequently emit more GHG to the atmosphere than forests. The overall average simulated annual net GHG balance for Wales under baseline climate (1961–1990) is equivalent to 0.2 t CO₂e ha^?1 y^?1 which gives an estimate of total annual net flux for Wales of 0.34 Mt CO₂e y^?1. Reducing N fertilizer by 20 and 40 % could reduce annual net GHG fluxes by 7 and 25 %, respectively. If the current N fertilizer application rate continues, predicted climate change by the year 2050 would not significantly affect GHG emissions or NPP from soils in Wales.     

Participatory Impact Assessment of Soil and Water Conservation Scenarios in Oum Zessar Watershed, Tunisia

Environmental threats and progressive degradation of natural resources are considered critical impediments to sustainable development. This paper reports on a participatory impact assessment of alternative soil and water conservation (SWC) scenarios in the Oum Zessar watershed, Tunisia. The first objective was to assess the impact of three SWC scenarios on key social, economic and environmental land use functions. The second objective was to test and evaluate the applicability of the 'Framework for Participatory Impact Assessment (FoPIA)' for assessing scenario impacts in the context of a developing country, in this case Tunisia. The assessed scenarios included: the originally planned SWC policy implementation at 85 % coverage of arable land of the watershed, the current implementation (70 %), and a hypothetical expansion of SWC measures to the entire watershed (100 %). Our results suggest that implementation of the SWC policy at 100 % coverage of arable land achieves the maximum socioeconomic benefit. However, if stakeholders' preferences regarding land use functions are taken into account, and considering the fact that the implementation of SWC measures also implies some negative changes to traditional landscapes and the natural system, SWC implementation at 85 % coverage of arable land might be preferable. The FoPIA approved to be a useful tool for conducting a holistic sustainability impact assessment of SWC scenarios and for studying the most intriguing sustainability problems while providing possible recommendations towards sustainable development. We conclude that participatory impact assessment contributes to an enhanced regional understanding of key linkages between policy effects and sustainable development, which provides the foundation for improved policy decision making.     

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.     

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.     

Optimization of methyl parathion biodegradation and detoxification by cells in suspension or immobilized on tezontle expressing the opd gene

The goal of this study was to optimize methyl parathion (O,O-dimethyl-O-4-p-nitrophenyl phosphorothioate) degradation using a strain of Escherichia coli DH5α expressing the opd gene. Our results indicate that this strain had lower enzymatic activity compared to the Flavobacterium sp. ATCC 27551 strain from which the opd gene was derived. Both strains were assessed for their ability to degrade methyl parathion (MP) in a mineral salt medium with or without the addition of glucose either as suspended cells or immobilized on tezontle, a volcanic rock. MP was degraded by both strains with similar efficiencies, but immobilized cells degraded MP more efficiently than cells in suspension. However, the viability of E. coli cells was much higher than that of the Flavobacterium sp. We confirmed the decrease in toxicity from the treated effluents through acetylcholinesterase activity tests, indicating the potential of this method for the treatment of solutions containing MP.     

Movement of unlined landfill under preloading surcharge

As organic solid waste is decomposed in a landfill and mass is lost due to gas and leachate formation, the landfill settles. Settlement of a landfill interferes with the rehabilitation and subsequent use of the landfill site after closure. This study examined the soil/solid waste movement at the Al-Qurain landfill in Kuwait after 15 years of closure as plans are underway for redevelopment of the landfill site that occupies about a km(2) with an average depth of 8-15m. Field experiments were conducted for 6 mo to measure soil/solid waste movement and water behavior within the landfill using two settlement plates with a level survey access, Casagrande-type piezometers, pneumatic piezometers, and magnetic probe extensometers. Previous results obtained indicated that biological decomposition of refuse continued after closure of the landfill site. The subsurface water rise enhanced the biological activities, which resulted in the production of increasing quantities of landfill gas. The refuse fill materials recorded a high movement rate under the imposed preloading as a result of an increase in the stress state. Up to 55% of the total movement was observed during the first 2 weeks of fill placement and increased to 80% within the first month of the 6-mo preloading test. Pneumatic piezometers showed an increase in water head, which is attributed to the developed pressure of gases escaping during the preloading period.