CONSTRUCTION OF A LOW COST AIR SAMPLER AND IT'S APPLICATION IN SAMPLING VOLATILE CARBONYL COMPOUNDS

lntcrcxt is expanding in measuring. concentrations of volatile organic compounds inbuildings since it is rccogniscd that many peoples' exposure to these compounds occur inthe indoor environment. However. such data are not available in Sri Lanka primarily dueto lack 01"proper equipment for quantitation and their high maintenance cost. This paperdcxcribcx the construction of a low cost air sampler (Rs. 40()/=) using commonly availablematerials.The air sampler contains a muffler fan to pull .unhient air though a filrcrts) and/or a bed ofsorhcnt material. which are housed in a variable length pye tube. Battery poweredmuffler fan and lightweight are two of the convenient features of this air sampler thatminimisc operational and transportation difficulties to the user.Vularilc carbonyl compounds such as formaldehyde acetaldehyde and acetone arecommonly found in indoors ambient air due to the combustion sources and emissions fromsvnthcric household products. Since formaldehyde is a known carcinogen andacetaldehyde is a suspected carcinogen compound. they were selected as the modelcompounds for the evaluation of constructed sampler. A filter paper spiked with 2. 4-dinitrophcnylhydruzcnc is used to collect the airborne carbonyl compounds at a flow rate ofI.X Cill'/SCC. Filters were sonicated in methanol and extracts were separated using a C,xcolumn for qu.uuitation at lSO mm wavelength. Quanutaiion limits estimates thats.unpling of I () dm ' ambient air enables minimum quantitauon of O.S formaldehyde. 1.0acetaldehyde and 1.2 acetone accurately. The paper also reports quantified levels ofairborne carbonyls from different indoor environments.

Soil Moisture Initialization Error and Subgrid Variability of Precipitation in Seasonal Streamflow Forecasting

Offline simulations over the conterminous United States (CONUS) with a land surface model are used to address two issues relevant to the forecasting of large-scale seasonal streamflow: (i) the extent to which errors in soil moisture initialization degrade streamflow forecasts, and (ii) the extent to which a realistic increase in the spatial resolution of forecasted precipitation would improve streamflow forecasts. The addition of error to a soil moisture initialization field is found to lead to a nearly proportional reduction in streamflow forecast skill. The linearity of the response allows the determination of a lower bound for the increase in streamflow forecast skill achievable through improved soil moisture estimation, e.g., through satellite-based soil moisture measurements. An increase in the resolution of precipitation is found to have an impact on large-scale streamflow forecasts only when evaporation variance is significant relative to the precipitation variance. This condition is met only in the western half of the CONUS domain. Taken together, the two studies demonstrate the utility of a continental-scale land surface modeling system as a tool for addressing the science of hydrological prediction

DEVELOPMENT OF AN ENVIRONMENT FRIENDLY METHOD TO REMOVE THE COLORED COMPONENTS FROM INDUSTURIAL WASTE WATER

Nowadays, synthetic dye context is a vital component in the textile and dyeing industries.The garr ient factories in the free trade zone that are discharging dyes and other colouredcornpounds into waterways pollute the environment. In this project, attempts were made todesign an environment friendly methodology to degrade Azo dyes by means of Eco--efficient techniques. Optimum conditions were evaluated for the redox-degradation of theAzo dyes and some of the dyes that are used in garment industry. The fidelity of theproposed mechanism was confirmed by the spectroscopic and GC analyses. As a reducingagent, metallic iron has fulfilled all the requirements that are prescribed for green chemicalconcepts.The results presented in this report clearly demonstrate that Anthroquinone-2-sulphonicacid is a powerful catalyst, capable of accelerating the reaction rate by orders ofmagnitude. The powdered form of charcoal amalgamated with metallic iron hasfacilitated as a better substrate to adsorb the dye component improving the contacts ofreactant molecules with the catalyst and dye molecules. The experimental results revealedthat pH 4 is the optimum condition for the redox degradation of the dye, which isconfirmed by electrochemical, and thermodynamic calculations. The elevation of thereaction temperature has accelerated the reaction by several orders of magnitude. Todemonstrate the applications in real world a continuous flow reduction apparatus wasdesigned and constructed.

Problems of Migrant Workers in the Middle East A Case Study of Return Female Migrants in Sri Lanka

There is overwhelming evidence that the increase in labour migration from SriLanka to the Middle East (ME) was due to the rapid development of economic andsocial activities in oil exporting countries. Of a total of 248, 096 of Sri Lankans whohad migrated for employments there, 247, 119 had gone to the ME. The number offemale migrants has increased significantly over the last three decades. Approximatelyhalf of the estimated 214 million international migrants worldwide were females. In SriLanka, women migrants have increased for the period during 1996-2009 with theexception of 2008 where male comprised 51 percent of the total migrants. Thecontribution of formal foreign employment remittances to Sri Lankan economy wasLKR Million 382, 801 in 2009. Migration also alleviates unemployment and incomedeficiency among the poorer segments of Sri Lanka‟s population. Nevertheless,domestic women workers in ME are subjected to abuse, violence, salary discriminationsand inhuman working conditions. Limited research has been undertaken to identifyproblems of domestic women workers in ME. The objectives of this study were to;identify the problems faced by female migrants, examine the reasons for the identifiedproblems and identify the institutional intervention in the prevention of problems. Atotal of 60 female returnees including 39 from Kuliyapitiya West Divisional SecretariatDivision and 21returnees who had come to complain their problems to ForeignEmployment Bureau were selected for the study. The overall findings highlight that,83% of female migrants have been suffering from mental and physical harassment andsalary discriminations. They have also been deceived by job agents regarding theworkload and salaries. The study further revealed that the problems were highlydependent on migrant‟s age, gender, ethnicity, education level and pre-migrationtraining.Key words: Gender, Middle East, Female migrants, Returnees

INVESTIGATION OF SULFUR COMPOUNDS IN SELECTED STAGNANT WATER BODIES

Sulfur compounds, primarily in the form of sulfides (S2.), sulfites (50)'") andsulfates (50t) have been neglected but has a strong effect upon water quality.The dark colour sediments and strong unpleasant ordours often indicate the 52.contamination in aquatic bodies. To the best of our knowledge, no attempt hasbeen made to investigate these compounds and to asses their contribution to thedegradation of water quality. Both the bacteria and dissolved oxygen (DO) areplaying leading roles in determining the fate of 5 containing compounds inaquatic systems.In this investigation it was intended to study the possible relationships betweensulfur species and DO. Four urban stagnant water bodies effected by impropersewage disposal, industrial waste, wet and dry deposition of atmospheric 50/'were investigated along with a prawn farm and two coconut husk soaking pitsinherited with S compounds. These water bodies indicated the emission ofvolatile 5 compounds. These water bodies indicated the emission of volatile 5compounds From their characteristic rotten egg smell.Under this study 52., SO)·2 and 50t levels were monitored along with DO, pHand temperature to investigate the possible correlation method introduced byPawlak and Pawlak (1999) was employed in determination of 52. levels while allother parameters were measured by employing standard methods.Based on the results obtained, only S2. shows a significant correlation with DOunder ambient conditions. Finally, measured dissolved 52. levels were utilized todetermine the possible H25 emission levels. Calculations have shown that each ofthe water body is emitting gaseous H25 and in most cases, emission levels aregreater than the ordour thresholds accounting for the unpleasant smell near thesestagnant water bodies.*Correspondence author

Emission factors for selected PAHs and carbonyl compounds from locally available mosquito coils and joss stick brands

In recent years, numerous investigations have revealed that indoor air pollution has a subtle chemistrywhich produces a range of pollutants. Combustion sources (some of which can be eradicated fromindoors) have become the major contributor to the indoor air pollution and the pollutants emanatingfrom these sources can poses serious health threats. Two of the combustion sources which can beeliminated from indoor settings, burning mosquito coils and joss sticks, were investigated in this studywith the emphasis on the einissions of the carbonyl compounds and polycyclic aromatic hydrocarbons[PAHs].Both carbonyl compounds and PAHs are known health hazards which are ubiquitous in the indoorsdue to incomplete combustion of organic compounds as well as due to the off gassing from consumerproducts. Poor air circulations entrap the pollutants indoors elevating the exposure and hence thehealth risks. Seven mosquito coil brands (locally made) and eight joss stick brands (both locally andIndian made) were burned in a laboratory setting simulating the indoor conditions. All the smokeemanating from the combustion source was passed through a prototype sampler. The volatile carbonylcompounds were derivatized to non-volatile 2,4-dinitrophenyl hydrazones and PAHs were collectedseparately using methanol. The hydrazone derivatives of the carbonyl compounds and the PAHswere separated individually using reversed-phase HPLC and quantified using UV and fluorescencedetectors respectively.The average emission factors for mosquito coils were 266 ± 114 ug g' (formaldehyde), 94 ± 37 ug gI (acetaldehyde) and 67 ± 13 ug g' (acetone) compared to that of joss sticks 127 ±'18 ug g'(formaldehyde), 38 ± 11 ug g' (acetaldehyde) and 38 ± 11 ug s:' (acetone). The levels of acrolein,croton aldehyde and propanaldehyde were very low and they could not be quantified with significantaccuracy and precision.The emission factors for naphthalene, acenapthene, acenapthylene, fluorine, phenanthrene, anthracene,fluoranthene, pyrene, benzo[ a]anthracene, chrysene, benzo[b ]fluoranthene, benzo[k ]fluoranthene andbenzo[a]pyrene were 6.33 ± 1.00,9.45 ± 1.04, 2.44 ± 0.47,6.54 ± 0.54,9.07 ± 0.55,3.96 ± 0.98,4.63± 0.44, 0.64 ± 0.17, 1.52 ± 0.42,2.67 ±0.66, 0.25 ± 0.08, 0.21 ± 0.05 and 0.17 ± 0.15 ug g' respectivelyfor mosquito coils and the emission factors of joss sticks for the same compounds were 5.33 ± 0.94,7.80 ± 0.95, 2.14 ± 1.14,4.25 ± 1.04,4.79 ± 0.66,3.53 ± 0.42,5.04 ± 0.99, 0.44 ± 0.12, 1.14 ± 0.17,1.63 ± 0.63, 0.1 R :: 0.04, 0.23 ± 0.15 and 0.15 ±.06 /lg g-I respectively.In general, Indian joss stick brands emitted more PAHs and carbonyl compounds compared to thelocal brands. This research is an attempt to glance at the exposures which can be prevented throughsimple measures such as control Iing the indoor combustions.

Toxic Volatile Organic Compounds in Environmental Tobacco Smoke:Emission Factors for Modeling Exposures of California Populations

The primary objective of this study was to measure emission factors for selected toxic air in environmental tobacco smoke (ETS) using a room-sized environmental chamber. The emissions of 23 volatile organic compounds (VOCs), including 1,3-butadiene, three aldehydes and two vapor-phase N-nitrosarnines were determined for six commercial brands of cigarettes and reference cigarette 1R4F. The commercial brands were selected to represent 62.5% of the cigarettes smoked in California. For each brand, three cigarettes were machine smoked in the chamber. The experiments were conducted over four hours to investigate the effects of aging. Emission factors of the target compounds were also determined for sidestream smoke (SS). For almost all target compounds, the ETS emission factors were significantly higher than the corresponding SS values probably due to less favorable combustion conditions and wall losses in the SS apparatus. Where valid comparisons could be made, the ETS emission factors were generally in good agreement with the literature. Therefore, the ETS emission factors, rather than the SS values, are recommended for use in models to estimate population exposures from this source. The variabilities in the emission factors (pgkigarette) of the selected toxic air contaminants among brands, expressed as coefficients of variation, were 16 to 29%. Therefore, emissions among brands were generally similar. Differences among brands were related to the smoked lengths of the cigarettes and the masses of consumed tobacco. Mentholation and whether a cigarette was classified as light or regular did not significantly affect emissions. Aging was determined not to be a significant factor for the target compounds. There were, however, deposition losses of the less volatile compounds to chamber surfaces

Contribution of dissolved sulfates and sulfites in hydrogen sulfide emission from stagnant water bodies in Sri Lanka

Abstract Accumulation of sulfur-containing compounds and their bacterial mediated reductions have led to the emission of pungent odors from stagnant water bodies. This study is focused on the contribution of inorganic sulfur compounds in the emission of hydrogen sulfide. The measured dissolved oxygen levels have demonstrated good negative correlations with the dissolved sulfide levels implying the oxygen deficiency is the key for the reduction of sulfate ion and sulfite ion to sulfide ion. Particularly, the dissolved molar fractions of sulfide from the total dissolved sulfur compounds (sulfates, sulfites and sulfides) have a very good correlation with the dissolved oxygen for the stagnant water bodies except the artificially aerated prawn farms. For the stagnant water bodies with significant correlations, linear regressions are reported for them to be utilized in estimating one component of the regression from the measurement of the other. The measured data were further utilized to estimate the levels of hydrogen sulfide gas. The pH of the water bodies has confined much of the dissolved sulfides in the form of bisulfide ion and they can be easily escaped to the atmosphere upon acidification due to industrial discharges and/or acidic precipitations. The estimated levels of hydrogen sulfide just above the water surface were plotted for the most polluted stagnant water body in Sri Lanka for the pH range of 5-10 and temperature range of 25-35°C

What do We Know the Snow Darkening Effect Over Himalayan Glaciers?

The atmospheric absorbing aerosols such as dust, black carbon (BC), organic carbon (OC) are now well known warming factors in the atmosphere. However, when these aerosols deposit onto the snow surface, it causes darkening of snow and thereby absorbing more energy at the snow surface leading to the accelerated melting of snow. If this happens over Himalayan glacier surface, the glacier meltings are expected and may contribute the mass balance changes though the mass balance itself is more complicated issue. Glacier has mainly two parts: ablation and accumulation zones. Those are separated by the Equilibrium Line Altitude (ELA). Above and below ELA, snow accumulation and melting are dominant, respectively. The change of ELA will influence the glacier disappearance in future. In the Himalayan region, many glacier are debris covered glacier at the terminus (i.e., in the ablation zone). Debris is pieces of rock from local land and the debris covered parts are probably not affected by any deposition of the absorbing aerosols because the snow surface is already covered by debris (the debris covered parts have different mechanism of melting). Hence, the contribution of the snow darkening effect is considered to be most important "over non debris covered part" of the Himalayan glacier (i.e., over the snow or ice surface area). To discuss the whole glacier retreat, mass balance of each glacier is most important including the discussion on glacier flow, vertical compaction of glacier, melting amount, etc. The contribution of the snow darkening is mostly associated with "the snow/ice surface melting". Note that the surface melting itself is not always directly related to glacier retreats because sometimes melt water refreezes inside of the glacier. We should discuss glacier retreats in terms of not only the snow darkening but also other contributions to the mass balance