Impacts of Traffic-Induced Lead Emissions on Air, Soil and Blood Lead Levels in Beirut

Lead is a purely toxic heavy metal which induces a wide variety of adverse physiologic effects. Nevertheless, it has been mined and used for more than 8,000 years. Among the different contemporary sources of lead pollution, traffic-induced emissions from the combustion of leaded gasoline is of particular concern, as it can constitute more than 90 percent of total lead emissions into the atmosphere in congested urban areas where no phase-out activities have been adopted. Gasoline lead content and traffic volume are strongly correlated with concentrations of lead in various environmental media. In the absence of policies to reduce the use of lead in gasoline or to favor the use of unleaded gasoline, leaded gasoline remains the predominant grade in many countries. This paper assesses the status of lead pollution from the combustion of leaded gasoline in Beirut based on field measurements of lead in air and roadside dust of urban and rural/suburban areas and recent data on soil and blood lead levels. Average atmospheric lead concentrations was about 1.86 microg m(-3) at urban locations and 0.147 microg m(-3) at suburban locations. The analysis of roadside dust revealed an average lead level of 353 microg g(-1) along urban streets and 125 microg g(-1) along rural/suburban roads. Blood lead levels were also relatively high in comparison to countries where leaded gasoline has been phased-out.     

The effect of food waste disposers on municipal waste and wastewater management.

This paper examines the feasibility of introducing food waste disposers as a waste minimization option within urban waste management schemes, taking the Greater Beirut Area (GBA) as a case study. For this purpose, the operational and economic impacts of food disposers on the solid waste and wastewater streams are assessed. The integration of food waste disposers can reduce the total solid waste to be managed by 12 to 43% under market penetration ranging between 25 and 75%, respectively. While the increase in domestic water consumption (for food grinding) and corresponding increase in wastewater flow rates are relatively insignificant, wastewater loadings increased by 17 to 62% (BOD) and 1.9 to 7.1% (SS). The net economic benefit of introducing food disposers into the waste and wastewater management systems constitutes 7.2 to 44.0% of the existing solid waste management cost under the various scenarios examined. Concerns about increased sludge generation persist and its potential environmental and economic implications may differ with location and therefore area-specific characteristics must be taken into consideration when contemplating the adoption of a strategy to integrate food waste disposers in the waste-wastewater management system.     

Predicted performance of clay-barrier landfill covers in arid and semi-arid environments

Conventional landfill cover systems for municipal solid waste include low-permeability compacted clay barriers to minimize infiltration into the landfilled waste. Such layers are vulnerable in climates where arid to semi-arid conditions prevail, whereby the clay cover tends to desiccate and crack, resulting in drastically higher infiltration, i.e., lower cover efficiency. To date, this phenomenon, which has been reported in field observations, has not been adequately assessed. In this paper, the performance of a cover system solely relying on a clay barrier was simulated using a numerical finite element formulation to capture changes in the clay layer and the corresponding modified hydraulic characteristics. The cover system was guided by USEPA Subtitle-D minimum requirements and consisted of a clay layer underlying a protective vegetated soil. The intrinsic characteristics of the clay barrier and vegetative soil cover, including their saturated hydraulic conductivities and their soil-water characteristic curves, were varied as warranted to simulate intact or "cracked" conditions as determined through the numerical analyses within the proposed methodology. The results indicate that the levels of percolation through the compromised or cracked cover were up to two times greater than those obtained for intact covers, starting with an intact clay hydraulic conductivity of 10(-5)cm/s.     

Simulating industrial emissions using Atmospheric Dispersion Modeling System: Model performance and source emission factors

In this paper, the Gaussian Atmospheric Dispersion Modeling System (ADMS4) was coupled with field observations of surface meteorology and concentrations of several air quality indicators (nitrogen oxides (NO_X), carbon monoxide (CO), fine particulate matter (PM₁₀) and sulfur dioxide (SO₂)) to test the applicability of source emission factors set by the European Environment Agency (EEA) and the United States Environmental Protection Agency (USEPA) at an industrial complex. Best emission factors and data groupings based on receptor location, type of terrain and wind speed, were relied upon to examine model performance using statistical analyses of simulated and observed data. The model performance was deemed satisfactory for several scenarios when receptors were located at downwind sites with index of agreement d values reaching 0.58, fractional bias “FB” and geometric mean bias “MG” values approaching 0 and 1, respectively, and normalized mean square error “NMSE” values as low as 2.17. However, median ratios of predicted to observed concentrations “Cp/Co” at variable downstream distances were 0.01, 0.36, 0.76 and 0.19 for NO_X, CO, PM₁₀ and SO₂, respectively, and the fraction of predictions within a factor of two of observations “FAC2” values were lower than 0.5, indicating that the model could not adequately replicate all observed variations in emittant concentrations. Also, the model was found to be significantly sensitive to the input emission factor bringing into light the deficiency in regulatory compliance modeling which often uses internationally reported emission factors without testing their applicability.

Implications In the absence of site-specific source emission factors, the use of internationally reported emission factors without testing their validity may generate significant errors. Instead, recorded field measurements and meteorological data may be combined with atmospheric transport and dispersion models to better estimate source emissions, particularly in regulatory compliance studies. In this context, lower model performance is expected at higher wind speeds for most indicators such as CO, PM₁₀, and SO₂.     

Drivers,barriers and incentives to implementing environmental management systems in the food industry: A case of Lebanon

The shift in policy towards prevention and towards making producers responsible for the pollution they cause has lead corporations to limit environmental liabilities through the improvement of environmental performance. The implementation of an Environmental Management System integrates the precautionary and polluter pays principles into a firm's operations and demonstrates commitment to sustainable development. This research aims at assessing the factors influencing the implementation of ISO 14001 Environmental Management System in developing countries taking the Food Industry in Lebanon as a case example. For this purpose, primary data were collected using a field survey questionnaire that was administered to a representative sample of facilities. The results revealed that the food industry is generally more concerned with safety and quality issues rather than environmental issues. Following international food sector trend, improving environmental performance and enhancing company image are the most salient drivers to adopt ISO 14001. The lack of government support and stakeholder demand as well as the fact that ISO 14001 is not a legal requirement constitute the most salient factors hindering the adoption of the standard. Economical and organizational factors are the most significant incentives required to motivate the food industry to adopt ISO 14001. The industry is less likely to voluntarily consider adopting ISO 14001 before acquiring a quality management certification or until ISO 14001 certification gain more recognition in the international food sector. The study defines the foundations for developing strategies, policy reforms and incentive schemes to reduce the barriers of implementing ISO 14001.     

Emission assessment at the Burj Hammoud inactive municipal landfill: Viability of landfill gas recovery under the clean development mechanism

This paper examines landfill gas (LFG) emissions at a large inactive waste disposal site to evaluate the viability of investment in LFG recovery through the clean development mechanism (CDM) initiative. For this purpose, field measurements of LFG emissions were conducted and the data were processed by geospatial interpolation to estimate an equivalent site emission rate which was used to calibrate and apply two LFG prediction models to forecast LFG emissions at the site. The mean CH(4) flux values calculated through tessellation, inverse distance weighing and kriging were 0.188±0.014, 0.224±0.012 and 0.237±0.008lCH(4)/m(2)hr, respectively, compared to an arithmetic mean of 0.24l/m(2)hr. The flux values are within the reported range for closed landfills (0.06-0.89l/m(2)hr), and lower than the reported range for active landfills (0.42-2.46l/m(2)hr). Simulation results matched field measurements for low methane generation potential (L(0)) values in the range of 19.8-102.6m(3)/ton of waste. LFG generation dropped rapidly to half its peak level only 4yrs after landfill closure limiting the sustainability of LFG recovery systems in similar contexts and raising into doubt promoted CDM initiatives for similar waste.     

Assessment of public vs private MSW management: a case study

Public-private partnerships in urban environmental services have witnessed increased interest in recent years primarily to reform the weak performance of the public sector, reduce cost, improve efficiency, and ensure environmental protection. In this context, successful public-private partnerships require a thorough analysis of opportunities, a deliberate attention to process details, and a continuous examination of services to determine whether they are more effectively performed by the private sector. A comparative assessment of municipal solid waste collection services in the two largest cities in Lebanon where until recently municipal solid waste collection is private in one and public in the other is conducted. While quality of municipal solid waste collection improved, due to private sector participation, the corresponding cost did not, due to monopoly and an inadequate organizational plan defining a proper division of responsibilities between the private and the public sector.     

Temporal variation of leachate quality from pre-sorted and baled municipal solid waste with high organic and moisture content

Landfill leachate characterization is a critical factor in establishing a corresponding effective management strategy or treatment process. However, it is often difficult to forecast leachate quality because of a variety of influencing factors such as waste composition and landfill operations. This paper describes leachate formation mechanisms, summarizes leachate quality indicators, and investigates the temporal variation of leachate quality from pre-sorted and baled municipal solid waste characterized with high organic and moisture content. The purpose of the study is to evaluate the potential effects of waste composition and site-specific operational procedures on biodegradation processes and leachate quality at a field-scale landfill that receives in excess of 1800 tonnes per day of refuse. For this purpose, waste disposal and leachate generation rates were monitored and leachate samples were collected for a period of 18 months during the early stages of refuse deposition. Chemical analysis was performed on the samples and the temporal variation of several parameters were monitored including pH, COD, TOC, TDS, chlorides, sulfates, orthophosphates, nitrates, ammonia nitrogen, hardness, and heavy metals. Chemical concentration levels were related to biological activity within the landfill and the results indicated that: (1) pre-sorting and baling of the waste did not hinder waste stabilization; and (2) the high organic and moisture contents resulted in an extremely strong leachate, particularly at the onset of biodegradation processes, which can affect the leachate treatment facility.