Risk of polycyclic aromatic hydrocarbon (PAH) exposure from ingested food: the Azerbaijan case study

Risks due to polycyclic aromatic hydrocarbons (PAHs) exposure from food consumption for the population of Azerbaijan were determined using deterministic and probabilistic methods. The guidelines and methods described and presented in the United States Environmental Protection Agency (U.S. EPA) Risk Assessment Guidance for Superfund (RAGS) Part A was used in performing the risk assessments. The current study utilized concentration data from different sources representing international studies performed over the past decade to determine those food products that contribute the most exposure to PAHs through ingestion for the Azeri population. Due to lack of concentration data from middle-Eastern countries, only European countries were considered and used for this analysis. Using the benzo[a]pyrene (BaP) toxicity equivalency factors (TEFs) to adjust the concentrations of the individual PAH compounds to BaP equivalent concentrations, risk analyses were performed. Deterministic risk estimates fell within probabilistic risk estimates. Child risks were consistently four to seven times higher in magnitude than adult risks. Risk potentials determined for the food exposure pathway were also determined to be up to ten times higher in magnitude than risks determined from exposures due to other pathways such as soil contamination. It was observed that three major factors contributed to the variability in the assessment results, which were child and adult body weights, consumption rates of the different food groups, and the variances of the input data. The most prevalent pathways of PAH exposure from the dietary patterns of the Azerbaijani population were determined to be from bread and bakery products, milk and dairy products, and egg products.     

Sub-cooled and flashing liquid jets and droplet dispersion I. Overview and model implementation/validation

Many accidents involve two-phase releases of hazardous chemicals into the atmosphere. This paper describes the results of a third phase of a Joint Industry Project (JIP) on liquid jets and two-phase droplet dispersion. The aim of the project is to increase the understanding of the behaviour of sub-cooled non-flashing and superheated flashing liquid jets, and to improve the prediction of initial droplet size, droplet dispersion and rainout.Phase III of the JIP first included scaled experiments for materials with a range of volatilities (water, cyclohexane, butane, propane and gasoline). These experiments were carried out by Cardiff University including measurements of flow rate and initial droplet size across the full relevant range of superheats. See the companion paper II for further details of these experiments and the derivation of new refined correlations for droplet size distribution and Sauter Mean Diameter. Furthermore large-scale butane experiments were carried out by INERIS (France) to ensure that for more realistic scenarios the derived droplet size correlations are accurate.Model validation and model improvements were carried out by DNV Software, including validation of release rate and initial droplet size against the above scaled and large-scale experiments. New correlations for droplet size distribution and Sauter Mean Diameter (SMD) were implemented into the Phast discharge model. These were compared against a range of other droplet size and rainout correlations published in the literature, in conjunction with validation against an extensive set of experiments. It was shown that the new droplet size correlation agrees better against experimental data than the existing Phast correlation. To further improve the rainout prediction, the Phast dispersion model (UDM) was also extended to allow simultaneous modelling of a range of droplet sizes and distributed rainout (rather than rainout at one point).     

An approach to tackling the environmental and health impacts of municipal solid waste disposal in developing countries

Indiscriminate disposal of municipal solid waste in developing countries poses severe environmental and health threats. The study proposes a new method for dealing with these problems. The hybrid structural interaction matrix (HSIM) was used to prioritise major identifiable environmental health factors arising from improper solid waste disposal. The simplistic resource allocation model was adopted to ensure optimality in the allocation of resources to prioritised factors. The study indicates that tackling environmental health impacts from the most prioritised negative disposal factors through optimal allocation of resources, will either reduce or eliminate the impacts associated with subsequent less prioritised factors that are direct consequences of the highly prioritised negative factors. The method proposed will aid decision makers in knowing which set of systemic factors are to be given preference and to what extent at given periods in time.     

Modelling of discharge and atmospheric dispersion for carbon dioxide releases

This paper discusses the modelling of the discharge and subsequent atmospheric dispersion for carbon dioxide releases using extensions of models in the consequence modelling package Phast. Phast examines the progress of a potential incident from the initial release to the far-field dispersion including the modelling of rainout and subsequent vaporisation. The original Phast discharge and dispersion models allow the released chemical to occur only in the vapour and liquid phases. As part of the current work these models have been extended to also allow for the occurrence of liquid to solid transition or vapour to solid transition. This applies both for the post-expansion state in the discharge model, as well as for the thermodynamic calculations by the dispersion model. Solid property calculations have been added where necessary. The above extensions are generally valid for fluid releases including CO₂. Using the extended dispersion formulation, a sensitivity study has been carried out for mixing of solid CO₂ with air, and it is demonstrated that solid effects may significantly affect the predicted concentrations.     

Recapitulating potential environmental and industrial applications of biomass wastes

Journal of Material Cycles and Waste Management - The generation of biomass wastes is a huge concern as they have to be properly managed to ensure environmental wellbeing. This article examined...     

Concentrations,bioaccumulation, and health risk assessments of heavy metals in fishes from Nigeria’s freshwater: a general overview

Environmental Science and Pollution Research - Heavy metals (HMs) have attracted global attention due to their toxicity, persistence, and accumulation in aquatic fish in the polluted water...     

Retracted: Authentically leading groups: The mediating role of collective psychological capital and trust

Although there have been recent theoretical advances in what is increasingly being recognized as authentic leadership, research testing possible mediating processes and the impact on group‐level outcomes has not received attention. To help address this need, this study examined at the group level of analysis the role that collective psychological capital and trust may play in the relationship between authentic leadership and work groups' desired outcomes. Utilizing 146 intact groups from a large financial institution, the results indicated a significant relationship between both their collective psychological capital and trust with their group‐level performance and citizenship behavior. These two variables were also found to mediate the relationship between authentic leadership and the desired group outcomes, even when controlling for transformational leadership. Implications for future research and practice conclude the paper. Copyright © 2009 John Wiley & Sons, Ltd.     

Management of immunization solid wastes in Kano State, Nigeria

Inadequate management of waste generated from injection activities can have a negative impact on the community and environment. In this paper, a report on immunization wastes management in Kano State (Nigeria) is presented. Eight local governments were selected randomly and surveyed by the author. Solid wastes generated during the Expanded Programme on Immunization were characterised using two different methods: one by weighing the waste and the other by estimating the volume. Empirical data was obtained on immunization waste generation, segregation, storage, collection, transportation, and disposal; and waste management practices were assessed. The study revealed that immunization offices were accommodated in either in local government buildings, primary health centres or community health care centres. All of the stations demonstrated a high priority for segregation of the infectious wastes. It can be deduced from the data obtained that infectious waste ranged from 67.6% to 76.7% with an average of 70.1% by weight, and 36.0% to 46.1% with an average of 40.1% by volume. Non-infectious waste generated ranged from 23.3% to 32.5% with an average of 29.9% by weight and 53.9% to 64.0% with an average of 59.9% by volume. Out of non-infectious waste (NIFW) and infectious waste (IFW), 66.3% and 62.4% by weight were combustible and 33.7% and 37.6% were non-combustible respectively. An assessment of the treatment revealed that open pit burning and burial and small scale incineration were the common methods of disposal for immunization waste, and some immunization centres employed the services of the state or local government owned solid waste disposal board for final collection and disposal of their immunization waste at government approved sites.     

A comparison of fish tissue mercury concentrations from homogenized fillet and nonlethal biopsy plugs

The use of biopsy plugs to sample fish muscle tissue for mercury analyses is a viable alternative to lethal sampling; however, the practice has yet to be widely implemented in routine monitoring due to concerns about variability of mercury concentrations in fish muscle tissues. Here we examine distribution of mercury in fillets of four fish species (Walleye, Northern Pike, Smallmouth Bass and Lake Trout), suitability of left/right side of fillet for biopsy sampling, and appropriateness of re-using a biopsy punch. The results showed that average mercury concentrations in left and right fillets of fish are similar. Mercury concentrations in biopsy plug samples, taken from the anterior dorsal area of the fish fillet, were statistically equivalent to the mercury concentrations in homogenized fillets. There was no discernible cross contamination between samples when a biopsy punch was reused after washing in hot soapy water, and as such, biopsy punches can be recycled during sampling to reduce the sampling cost. If a tissue mass collected from a specific site on the fillet is insufficient, then we suggest sampling corresponding locations on the other fillet rather than sampling two adjacent sites on one fillet to obtain more tissue. The results presented here can improve the accuracy of fillet biopsy plug sampling, minimize fish mortality for mercury monitoring, and reduce labor and material costs in monitoring programs.