Carbonyls and non-methane hydrocarbons at a rural mountain site in northeastern United States

Measurements of carbonyls and C₂–C₆ non-methane hydrocarbons (NMHCs) were made in ambient air at a rural site at the summit of Whiteface Mountain (WFM) in New York State. Alkanes dominated in the samples, with ethane and propane making up about 55% of the total on a carbon-atom basis. Ethane, the longest-lived of the NMHCs, showed a mixing ratio in the range of 0.86–2.1 ppbv. Photochemical ageing analysis indicated an anthropogenic influence on the NMHC levels. The photochemical reactivity of the hydrocarbons, calculated in terms of propylene-equivalent concentration, was dominated by alkenes (propene and ethene), which accounted for 74% of the total NMHC sum. Air mass back-trajectories have been used to investigate the origin of the observed NMHCs and carbonyls. Higher concentrations were found when air masses arrived from the midwestern US corridor. Acetone was the most abundant species, comprising from 31% to 53% of the total detected carbonyls, followed by MEK (15–53%), HCHO (7–39%), and CH₃CHO (7–19%). Average concentrations were determined to be 1.61 ppbv for CH₃C(O)CH₃, 1.40 ppbv for MEK, 1.16 ppbv for HCHO, and 0.49 ppbv for CH₃CHO. The variations in carbonyl concentrations were observed to follow patterns similar to variations in O₃ concentrations, typical of secondary products. Correlations and statistical analysis of the carbonyls and NMHCs were performed, and showed that most of the compounds derived from mixing and photochemical transformation of long-range transported pollutants from the major source areas. Ranking of the carbonyls with respect to removal of the OH radical showed HCHO to be the most important species, followed by CH₃CHO, MEK, and CH₃C(O)CH₃.     

Lead Content of Petrol and Diesel and its Assessment in an Urban Environment

Pakistan is one of the few countries in Asia thatcontinues to use only leaded-petrol as vehicular fuel. Theconcentration of Pb in its petrol reported in 1991 was thehighest (1.5 – 2.0 g Pb L^-1) of all produced by the various Asiancountries and far exceeded the WHOs guideline of 0.15 g Pb L^-1. We have undertaken a study to trace and quantify this toxicelement in the environs of Karachi, Pakistans major metropolis,having more than 30% of the nations total number of vehicles.In this article we report the Pb contents of petrol and dieselcurrently manufactured and marketed in the city. Samples of`Regular petrol collected in 1999 was found to contain 0.363 gPb L^-1 (range: 0.335 – 0.390 g Pb L^-1), a factor of 5 lower than thatmarketed prior to 1991. Its concentration in diesel fuel was muchlower (0.017 g Pb L^-1). Based on the available statistical data onthe type and volume of vehicular traffic, we assessed that thecurrent lead emission from vehicular traffic into the atmosphereis 391 metric tons a year, which is a factor of 2.7 lower thanthat estimated for 1989.     

Food Security in Protracted Crises: Building More Effective Policy Frameworks

This paper considers the principal elements that underpin policy frameworks for supporting food security in protracted crisis contexts. It argues that maintaining the food entitlements of crisis-affected populations must extend beyond interventions to ensure immediate human survival. A 'policy gap' exists in that capacities for formulating policy responses to tackle the different dimensions of food insecurity in complex, fluid crisis situations tend to be weak. As a result, standardised, short-term intervention designs are created that fall short of meeting the priority needs of affected populations in the short and long term and only partially exploit the range of policy options available. The paper discusses key attributes of agency frameworks that could support more effective policy processes to address longer term as well as immediate food security needs. Additionally, it points to some main challenges likely to be encountered in developing such frameworks and, with the participation of beneficiaries, translating them into effective action.     

Monitoring of Ganga Water and Sediments Vis-à-Vis Tannery Pollution at Kanpur (India): A Case Study

The leather industry, besides being a major contributorto the Indian national economy, is unfortunately alsoone of the major polluters. The present articlediscusses the influence of the wastes on thephysicochemical characteristics of the Ganga water andsediments. Two sampling sites have been chosen atKanpur, the first before and the second after thepoint where tanneries are located. The samephysicochemical parameters which have been determinedin the wastes have been monitored at these two sitesfor two seasons. The results reveal that mostparameters increase as the river traverses betweenthese two points. The increase in values of parameterssuch as BOD, COD, Cl^-, and total solids could bedue to the domestic wastes just as much as to thetannery wastes. Phenols and sulfides, can also comefrom other sources, but their probability of comingfrom tanneries is higher. However, chromium is oneparameter which can primarily be identified tooriginate from the tanneries. The speciation of thesediments for chromium reveals that the leakage ofchromium into the Ganga is taking place at the secondsite. There is almost a ten fold increase in chromiumat the second site as compared to the first. At thefirst site the surface chromium is primarily in theresidual fraction while at the second site it is inthe Fe–Mn oxide fractions.     

Former DDT factory in Pakistan revisited for remediation: severe DDT concentrations in soils and plants from within the area

A factory in Amman Garh near Nowshera, Khyber Pakhtunkhwa, Pakistan, produced dichlorodiphenyltrichloroethane (DDT) from 1963–1994. Consequently, earlier papers reported a soil contamination in the per mille range inside the former factory wall (88 m?×?106 m) and up to 10 mg/kg of DDT in the surroundings in 2005–2007. The site within the factory wall was remonitored systematically in 2011 to complement the earlier data as a prerequisite for remediation, to put them in exposure context in a population developing area, and to suggest and evaluate the optimal remediation technique for the site. The contamination was drastically higher than the earlier published data, and the sum of DDT and its metabolites (ΣDDT) was up to 65 % in the soil. Grasses, shrubs, and trees growing in this severely contaminated site had 50–450 mg/kg_dw of ΣDDT. Thus, people living nearby and husbandry as well as wild animals are heavily exposed to DDT. The semiarid climate favors wind drift and deposition of the pollutant. Additionally, DDT from products of herbivore animals feeding on the contaminated plants will enter the food web. To overcome the exposure and distribution of the DDT, the site within the factory wall was capped with 1.5 m of soil. This remediation technique represents the easiest and least expensive solution. Nevertheless, DDT can still evaporate or leach, and groundwater can rise in this flood-prone area and thereby become contaminated, especially because a binding layer is missing.     

The geoenvironmental cycle of cadmium: a case study

Amidst the hue and cry about anthropogenic sources of pollution, there are regions in the world facing silent metal discharges purely due to geochemical factors. The present investigation relates to such a situation and deals with the non-anthropogenic discharge of cadmium into the local environment. The phosphorite rocks of the Roorkee area of India contain cadmium and, particularly as these are used in the manufacture of superphosphate, the rocks could lead to the large-scale disbursement of cadmium into the open environment. The area under study has soil rich in cadmium-containing minerals, as a result of which water is likely to leach out mobile cadmium and the ground water and crops could become contaminated. This is evident from the high values of cadmium in the tap water and food samples in the area. The Ganga and the Yamuna, the two major rivers traversing the area that originate in the central crystalline rocks of the Himalayas, show high cadmium values at Rishikesh and Dakpathar. Moreover, the sediments of these rivers have cadmium in easily bioavailable form. Food samples and milk analysed from the area show, in some cases, cadmium levels above the safety limits. This high exposure to cadmium is probably causing ailments so far unreported.