The gas-liquid partitioning behavior of major odorants (acetic acid, propionic acid, isobutyric acid, n-butyric acid, i-valeric acid, n-valeric acid, hexanoic acid, phenol, p-cresol, indole, skatole, and toluene (as a reference)) commonly found in microbially digested wastewaters was investigated by two experimental approaches. Firstly, a simple vaporization method was applied to measure the target odorants dissolved in liquid samples with the aid of sorbent tube/thermal desorption/gas chromatography/mass spectrometry. As an alternative method, an impinger-based dynamic headspace sampling method was also explored to measure the partitioning of target odorants between the gas and liquid phases with the same detection system. The relative extraction efficiency (in percent) of the odorants by dynamic headspace sampling was estimated against the calibration results derived by the vaporization method. Finally, the concentrations of the major odorants in real digested wastewater samples were also analyzed using both analytical approaches. Through a parallel application of the two experimental methods, we intended to develop an experimental approach to be able to assess the liquid-to-gas phase partitioning behavior of major odorants in a complex wastewater system. The relative sensitivity of the two methods expressed in terms of response factor ratios (RFvap/RFimp) of liquid standard calibration between vaporization and impinger-based calibrations varied widely from 981 (skatole) to 6,022 (acetic acid). Comparison of this relative sensitivity thus highlights the rather low extraction efficiency of the highly soluble and more acidic odorants from wastewater samples in dynamic headspace sampling.
BackgroundPakistan has a large population of tobacco users, with about 24 million adults consuming tobacco products in one form or another. There is a dearth of research on the impact of a reduction in tobacco use on Pakistan’s economy which can inform policy-makers on the extent that tobacco control measures would affect macroeconomic indicators such as output and employment.ObjectivesThe objective of this study is to quantify the changes in output, income and employment resulting from changes in cigarette consumption and to quantify the impact of such changes on the overall economy.MethodologyThe study uses the input–output table for the fiscal year 2010–2011 for Pakistan’s economy, to estimate the output, income and employment multipliers. The Leontief input–output model is used to estimate the sectorwise multiplier effects. It estimates direct, indirect and consumption-induced effects of changes in tobacco use on the economy.ResultsThe cigarette industry’s share in large-scale manufacturing and industrial employment is 1.1% and 0.3%, respectively. The estimates of gross output, income and employment multipliers for the cigarette industry have relatively small magnitudes indicating minimal impact on the economy. A simulation analysis based on the latest estimates of price elasticity of cigarette and input–output multipliers, shows that a 10% increase in price will lead to an 11% reduction in cigarette consumption, which translates into annual savings of Pakistani Rupees (Rs) 16 billion by households. Reduction in cigarette consumption will allow individuals to spend their savings on other commodities. For example, spending this amount on food items will lead to a net increase of Rs 40 billion annual output of the economy.ConclusionReduction in tobacco consumption will lead to initial losses to the economy but there will be considerable gains in output, employment and income due to redistribution of tobacco expenditures.
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