Partition Constants and Adsorption/Desorption Hysteresis for Volatile Organic Compounds on Soil from a Louisiana Superfund Site

The adsorption of four volatile organic compounds (1,4-dichloro-benzene, 1,2-dichloroethane, 1,2,2-trichloroethane and 1,1,2,2,-tetrachloroethane) on three soil types from a Superfund site (Petroprocessors Inc) in Baton Rouge, LA was studied with the purpose of obtaining an overall correlation for inclusion in a groundwater transport model being developed for site remediation. The soil-water partition constant, K_d was determined using a standard ASTM procedure (E–1195–87). Using the data for different soil types (fraction organic carbon between 0.11% and 1.13%) and different mineral surface areas (7 to 45 m²/g), the organic carbon contribution (K_oc) and the mineral matter contribution (K_min) to the partition constant were determined. The soils obtained were either from the Pleistocene period or recent shallow deposits at the site. Both log K_oc and log K_min were linearly correlated to log K_ow, the octanol-water partition constant. This data provided the basis for obtaining a general correlation for K_d on different soil types at the site. The predicted values were in agreement with that for a composite soil from the same site. The desorption of compounds from the high clay soil after the 24 hour adsorption period was observed to show a biphasic behavior, namely, an easily desorbed fraction and a desorption resistant fraction. The easily desorbed fraction was found to be satisfactorily predicted using the conventional K_d as obtained from the adsorption experiment. The slowly desorbing fraction had a time constant of several weeks. The concentration in the desorption resistant compartment was found to be dependant on the initial amount of contaminant available for adsorption. The aqueous phase concentration in equilibrium with the desorption resistant fraction was found to be 8 g/L for dichlorobenzene and 12 g/L for dichloroethane.     

Environmental contaminants and productivity in an extinct heronry at Charleston Harbor,South Carolina,U.S.A., 1984

Our objectives were to collect information on contaminant levels and productivity of wading birds at the Drum Island heronry in Charleston Harbor, South Carolina, before diversion of the Cooper River took place in 1985. The diversion was expected to reduce water flow by 80% into the Harbor, thereby concentrating industrial effluents near the heronry with potentially harmful effects. Hatching success of white ibises (Eudocimus albus) in 1984 averaged 66% and 1.0 chick per nest survived to three weeks post-hatch. Fresh eggs collected from a sample of nests contained only background levels of DDT, DDE, and Dieldrin; no PCBs, diphenyl ethers, or styrenes were detected. Pesticide residues in eggs were not correlated (P>0.05) with productivity in corresponding nests. Heavy metals and selenium in tissues of wading bird chicks were also representative of background levels. Follow-up studies after the diversion of the Cooper River were not feasible because the heronry was abandoned beginning in 1985. However, our baseline results will be useful in determining potential contaminant effects due to diversion of the Cooper River should wading birds return to Drum Island in the future.     

Mercury, Methylmercury, and Selenium Concentrations in Eggs of Common Loons (Gavia immer) from Canada

Concentrations of Hg and Se were determined for a total of 125Common Loon (Gavia immer) eggs collected from lakes in Alberta, Saskatchewan, Ontario, Quebec, New Brunswick and NovaScotia, Canada between 1972 and 1997. Resulting data were compared to Hg and/or Se concentrations known or suspected tocause reproductive impairment in birds. Organic (methyl) Hg analyses were also performed on a subset of 24 loon eggs. Thirty-nine of 125 eggs had total Hg levels exceeding those (0.6 g g^-1 ww, or 2.5 g g^-1 dw)previously reported to be associated with reproductive impairment in common loons (Barr, 1986), and 9 of 125 eggshad Hg concentrations higher than the level associated withreproductive impairment in birds generally 1 g g^-1 ww; (Thompson, 1996). Selenium concentrations in loon egg samples were less than levels known to cause reproductiveimpairment in birds. A weak but significant positive correlation was observed between egg-Hg and -Se concentrations(r = 0.511, p < 0.05). On average, methylmercury accounted for about 87% of total Hg in 24 eggs analysed for both total and organic Hg. In this subset of eggs, the relationship between organic (methyl) Hg and Se was significant (r = 0.538, p = 0.007) while that found between inorganic Hg and Se in the same eggs was not significant (r = 0.353, p = 0.091). This relationship was unexpected and was contrary to relationships established for organic and inorganic Hg vs. Se in adult loon liver and kidney tissue (Scheuhammer et al., 1998b).     

Environmental Assessment of the Impact of Ozone to the Neuston of the Sea-Surface Microlayer of the Gulf of Mexico

Substantial amounts of NOx (146 000 t/y) and total hydrocarbons (294 000 t/y) are released to the marine atmosphere by the large number of oil and gas operations over Federal waters of the Gulf of Mexico (GOM). Under appropriate meteorological conditions these emissions react to form ozone (0–54 g/m3 over-water) which can affect the marine environment. Using a dry deposition model, this work examines the amount of ozone derived from oil and gas offshore operations and deposited in the sea surface of the Gulf of Mexico, and assesses its impact on the neuston of the sea-surface microlayer. Surface integrated estimates of ozone deposited from oil and gas operations over the sea surface ranges from 400 kg to 1800 kg which results in sea surface concentrations of 15 g/m3. This estimate and the actual toxic ozone levels suggest no acute, toxic impacts to the neuston. However, indirect effects may occur through changes to the pelagic foodwebs and organic carbon pathways. Another potential pathway for ozone impacting the environment is through the production of bromate. Based on the concentrations and time scales (11–139 days) only sublethal effects appear to occur, but uncertainties associated with this assessment need to be further studied. From an ecological perspective, the environmental impacts and risks of NOx and VOC discharges from offshore platforms need to be assessed for neuston and other components of the marine ecosystem.     

The effects of salinity,temperature and sediment on the toxicity of copper to juvenile Hediste (Nereis) diversicolor (O. F. Muller)

Without sediment, increasing salinity (7.3 to 29.2) and increasing temperature (12 to 22 °C) reduced the toxicity of copper to juvenile Hediste diversicolor. The LC₅₀ values ranged from 357 gL^-1 in 7.3 to 513 g L^-1 in 29.2 at 12°C and from 247 to 500 g L^-1 at 22°C. In deionized water all the juvenile were dead in all solutions to which copper was added (100 to 600 g L^-1). Dead worms were swollen and everted their pharynxs. In higher doses of copper (500 to 600 g L^-1) the worms were abnormal in behaviour in all salinities (0 to 29.2). The ability to swim or crawl was disturbed.With sediments increasing temperature and increasing salinity increased the toxicity of copper to the worms. The LC₅₀ values ranged from 3200 to 4100 g L^-1 at 22°C. The response of the juvenile to copper was antagonistic to increasing temperature and salinity and synergistic to increasing salinity and increasing temperature without and with the sediment respectively.     

Trihalomethane Formation Potential and Concentration Changes During Water Treatment at Mumbai (India)

The treated water at the outlet oftreatment plants and representative servicereservoirs of Mumbai city have been evaluatedfor trihalomethane formation potential in1995–1996. Chloroform, dichlorobromomethane,chlorodibromomethane and bromoform have beenmonitored during monsoon, winter and summer.The levels of chloroform are found above theregulated WHO guideline value of 200 g L^-1 in final water during postmonsoon atGhatkopar (226 g L^-1), Malbar (210.3 g L^-1) and Tulsi (231.26 g L^-1).     

A Survey of Trace Metals in Vegetation, Soil and Lower Animal Along Some Selected Major Roads in Metropolitan City of Lagos

The concentration of trace metals (Cd, Cu, Pb and Zn) in a total of 144 samples of grass, soil and lower animal (earthworm, Lybrodrilus violaceous) were collected and analysed for their metallic content. Levels of cadmium ranged from 0.01–0.07 g g^–1; 0.01–0.12 g g^–1 and from trace–0.05 g g^–1 dry weight for plant, soil and animal samples respectively. Mean concentration of copper ranged 0.10–1.48 g g^–1; 0.10–2.90 g g^–1 and 0.01–0.08 g g^–1 for samples in similar order as above. The levels of Pb varied from 0.01–0.14 g g^–1; 0.02–0.23 g g^–1 and from trace–0.07 g g^–1 while that of Zn ranged from 0.19–1.80 g g^–1; 0.51–3.35 g g^–1and 0.01–0.08 g g^–1 also in the same order of samples as mentioned above. Levels of metals in soil samples were higher than the background levels with the exception of Zn but lower than European Union (EU) limits. The results generally revealed the presence of metals in plant and animal samples and metal dynamics up the food chain is highly possible. Acceptable recoveries of the spiking experiment validate the experimental protocol.     

An Analysis with the CERT Model of the FSU Market Power in the Carbon Emissions Trading Market

This paper aims to assess the consequences of the amendments made to the Kyoto Protocol during COP 7 in Marrakech. The major issue of hot air and CDM transaction costs is examined using the CERT model to show that primary supply regions, typically those with hot air availability, might control the emissions reduction permit supply market and maximise net export revenues of permit supply by withholding 40 to 60% of available hot air credits. The assumption that primary permit suppliers control permit price via a restriction of hot air supply to the market will inadvertently leave a portion of the market share open to non-Annex B CDM supply, despite potentially extreme variance in CDM transaction costs. A summary table of policy implications on the emissions reduction permit market is also included.     

Forest-Climate Interactions in the Quetico-Superior Ecotone (Northwest Ontario and Northern Minnesota)

Acute ecological changes in North American boreal forests in this century are attributed to an array of factors including human activities. In the Quetico-Superior Ecotone of Northwest Ontario and Northern Minnesota warmer, drier climate conditions since mid-century have concurred with extensive manipulation of regional forests by fire suppression and clear-cut logging. Predicted effects of climate changes expected for the next century could compete with transformations in these systems over the past 10 000 yr. The degree of alteration of natural processes and patterns in North American boreal forests requires implementation of realistic strategies to ensure that sufficiently large tracts of these systems maintain their natural integrity.     

Insecticide Contamination of Jamaican Environment. V. Island-Wide Rapid Survey of Residues in Surface and Ground Water

Residues of organochlorines and organophosphates were determined by gas chromatography in water and sediment from 26 locations in 17 major rivers, 7 natural springs and 13 wells across Jamaica. Samples were collected on only one occasion between May and July, 1994. Residues of endosulfan were detected in all but three rivers; -endosulfan in 15 samples of sediment (0.9–108.1, mean = 28.93, S.E. = 7.198 g kg-1) and 13 of water (0.01–0.35, mean = 0.11, S.E. = 0.035 g L-1), -endosulfan in 5 sediment (15.29–49.35, mean = 30.56, S.E. = 7.132 g kg-1) and 12 water (0.05–0.31, mean = 0.14, S.E. = 0.031 g L-1) samples, and endosulfan sulphate in waters of three rivers (0.003–0.244 g L-1). Chlorpyrifos was present in 9 sediment (0.423-135.2, mean = 18.38, S.E. = 10.699 g kg-1) and two water (0.001–0.022 g L-1) samples, diazinon and ethoprophos in the sediment of one river each. Mean levels (g L-1) of and isomers and sulphate of endosulfan were 0.16 (S.E. = 0.057), 0.12 (S.E. = 0.036) and 0.15 (S.E. = 0.089), respectively, in four of the seven springs and 0.23 (S.E. = 0.052), 0.11 (S.E. = 0.029) and 0.26 (S.E. = 0.088), respectively, in seven of the thirteen wells monitored.     

Biomagnification factors (fish to Osprey eggs from Willamette River,Oregon, U.S.A.) for PCDDs,PCDFs, PCBs and OC pesticides

A migratory population of 78 pairs of Osprey (Pandion haliaetus) nesting along the Willamette River in westernOregon was studied in 1993. The study was designed to determinecontaminant concentrations in eggs, contaminant concentrationsin fish species predominant in the Ospreys diet, andBiomagnification Factors (BMFs) of contaminants from fish specieseaten to Osprey eggs. Ten Osprey eggs and 25 composite samplesof fish (3 species) were used to evaluate organochlorine (OC)pesticides, polychlorinated biphenyls (PCBs), polychlorinateddibenzo-p-dioxins (PCDDs), and polychlorinated dibenzofurans(PCDFs). Mercury was also analyzed in fish. Geometric meanresidues in Osprey eggs were judged low, e.g., DDE 2.3 g g^-1 wet weight (ww), PCBs 0.69 g g^-1, 2,3,7,8-TCDD 2.3 ng kg^-1, and generally well below known threshold values for adverse effects on productivity, and the population was increasing. Osprey egg residue data presentedby River Mile (RM) are discussed, e.g., higher PCDDs were generally found immediately downstream of paper mills and eggsfrom the Willamette River had significantly elevated PCBs and PCDDs compared to reference eggs collected nearby in the CascadeMountains. Prey remains at nest sites indicated that the Largescale Sucker (Catostomus macrocheilus) and NorthernPikeminnow (Ptychocheilus oregonensis) accounted for an estimated 90.1% of the biomass in the Osprey diet, and composite samples of these two species were collected from different sampling sites throughout the study area for contaminant analyses. With the large percentage of the fishbiomass in the Osprey diet sampled for contaminants (and fisheaten by Ospreys similar in size to those chemically analyzed),and fish contaminant concentrations weighted by biomass intake, a mean BMF was estimated from fish to Osprey eggs for the largeseries of contaminants. BMFs ranged from no biomagnification(0.42) for 2,3,7,8-TCDF to 174 for OCDD. Our findings for themigratory Osprey were compared to BMFs for the resident HerringGull (Larus argentatus), and differences are discussed. Webelieve a BMF approach provides some basic understanding ofrelationships between contaminant burdens in prey species offish-eating birds and contaminants incorporated into their eggs,and may prove useful in understanding sources of contaminants inmigratory species although additional studies are needed.     

Environmental Contaminants in Blood, Hair, and Tissues of Ocelots from the Lower Rio Grande Valley, Texas, 1986–1997

The ocelot (Felis pardalis) isan endangered neotropical cat distributed within asmall range in the Lower Rio Grande Valley (LRGV), inTexas, U.S.A. Studies of the impacts of environmentalcontaminants in wild cats are few. Approximately onefourth of the estimated population (about 100) ofocelots in the LRGV was sampled to evaluate theimpacts of chlorinated pesticides, polychlorinatedbiphenyls, and trace elements on the population. Hairwas collected from 32 ocelots trapped between 1986–1992,and blood was collected from 20 ocelots trappedbetween 1993–1997. A few blood samples were obtainedfrom individuals recaptured two or three times. Tissue samples from 4 road-killed ocelots were alsoanalyzed. DDE, PCBs, and Hg were some of the mostcommon contaminants detected in hair and blood. MeanHg levels in hair ranged from 0.5 to 1.25 g g^-1 dw,Se from 1.5 to 3.48 g g^-1 dw, and Pb from 0.56 to26.8 g g^-1 dw. Mean DDE concentrations in plasma ranged from 0.005 g g^-1 ww to 0.153 g g^-1 ww, and PCBs ranged from 0.006 g g^-1 ww to 0.092 g g^-1 ww. Mean Hg levels in red blood cells rangedfrom 0.056 g g^-1 dw to 0.25 g g^-1 dw. Concentrations of DDE, PCBs, or Hg, did not increasesignificantly with age, although the highestconcentrations of DDE and Hg were found in olderanimals. Overall, concentrations of DDE, PCBs, and Hgwere low and at levels that currently do not pose anythreat to health or survival of the ocelot. This isfurther supported by good reproduction of the ocelotin the LRGV, where adult females averaged about 1.5kittens/litter. Thus, it seems that the current majorthreat to recovery of the ocelot in the LRGV may behabitat loss, although potential impacts of newgeneration pesticides, such as organophosphorus andcarbamate insecticides need further study.     

Application of CFD Methods for Modelling in Air Pollution Problems: Possibilities and Gaps

Different urban air pollution problems deal with complex structure of air flows and turbulence. For such problems the Computer Fluid Dynamics (CFD) methods become widely used. However, this approach despite a number of advantages has some problems. Experience of use of CFD tools for development of models and suggestions of their applications for a local scale air pollution over a complex terrain and stable stratification are discussed in this paper, including: Topography and complex geometry: choose of the co-ordinate system and computer grid; Turbulence closure for air pollution modelling: modified k- model for stable stratified ABL; Boundary conditions for vertical profiles of velocity for stable-stratified atmosphere; Effects of the radiation and thermal budget of inclined surfaces to dispersion of pollutants; Artificial sources of air dynamics and circulation.Some examples of CFD applications for air pollution modelling for a flat terrain, mountainous area, mining open cast and indoor ventilation are discussed. Modified k- model for stably-stratified ABL is suggested. Due to the isotropic character of the k- model a combination of it in vertical with the sub-grid turbulence closure in horizontal can be more suitable for ABL. An effective scheme of boundary conditions for velocity profiles, based on the developed similarity theory for stable-stratified ABL, is suggested. Alongside with the common studies of atmospheric dispersion, the CFD methods have also demonstrated a good potential for studying anthropogenic and artificial-ventilation sources of air dynamic and circulation in local-scale processes of air pollution.     

Aircraft-Induced Noise Levels in Some Residential Areas of Delhi

The measurements of aircraft-induced noise levels in some residential areas in the capital city of India were carried out in the month of April and May, 1996. Four areas were chosen which were located underneath the flight path. It has been found that average increase in noise levels over and above the background levels is more than 20 dBA except in case of the most distant site where it is 11 dBA. A good correlation has been found between average peak noise levels (dBA) and the population response in terms of annoyance.     

Microbiological characteristics in a zero-valent iron reactive barrier

Zero-valent iron (Fe⁰)-based permeable reactive barriertreatment has been generating great interest for passivegroundwater remediation, yet few studies have paid particularattention to the microbial activity and characteristics withinand in the vicinity of the Fe⁰-barrier matrix. The presentstudy was undertaken to evaluate the microbial population andcommunity composition in the reducing zone of influence byFe⁰ corrosion in the barrier at the Oak Ridge Y-12 Plantsite. Both phospholipid fatty acids and DNA analyses were usedto determine the total microbial population and microbialfunctional groups, including sulfate-reducing bacteria,denitrifying bacteria, and methanogens, in groundwater andsoil/iron core samples. A diverse microbial community wasidentified in the strongly reducing Fe⁰ environment despitea relatively high pH condition within the Fe⁰ barrier (up topH 10). In comparison with those found in the backgroundsoil/groundwater samples, the enhanced microbial populationranged from 1 to 3 orders of magnitude and appeared to increase from upgradient of the barrier to downgradient soil. Inaddition, microbial community composition appeared to change overtime, and the bacterial types of microorganismsincreased consistently as the barrier aged. DNA analysisindicated the presence of sulfate-reducing and denitrifyingbacteria in the barrier and its surrounding soil. However, theactivity of methanogens was found to be relatively low,presumably as a result of the competition by sulfate/metal-reducing bacteria and denitrifying bacteria because of the unlimited availability of sulfate and nitrate in the site groundwater. Results of this study provide evidenceof a diverse microbial population within and in the vicinity ofthe iron barrier, although the important roles of microbial activity, either beneficially or detrimentally, on the longevityand enduring efficiency of the Fe⁰ barriers are yet to be evaluated.     

Antibiotic resistance analysis of fecal coliforms to determine fecal pollution sources in a mixed-use watershed

Antibiotic resistance analysis was performed on fecal coliform(FC) bacteria from a mixed-use watershed to determine thesource, human or nonhuman, of fecal coliform contamination. The study consisted of discriminant analysis of antibioticresistance patterns generated by exposure to fourconcentrations of six antibiotics (ampicillin, gentamicinsulfate, kanamycin, spectinomycin dihydrochloride,streptomycin sulfate, and tetracycline hydrochloride). Areference database was constructed from 1125 fecal coliformisolates from the following sources: humans, domestic animals(cats and dogs), agricultural animals (chickens, cattle, andhorses), and wild animals. Based on similar antibioticresistance patterns, cat and dog isolates were grouped asdomestic animals and horse and cattle isolates were grouped aslivestock. The resulting average rate of correctclassification (ARCC) for human and nonhuman isolates was94%. A total of 800 FC isolates taken from the watershedduring either a dry event or a wet event were classifiedaccording to source. Human sources contribute a majority(>50%) of the baseflow FC isolates found in the watershed inurbanized areas. Chicken and livestock sources areresponsible for the majority of the baseflow FC isolates foundin the rural reaches of the watershed. Stormwater introducesFC isolates from domestic (16%) and wild (21%) sourcesthroughout the watershed and varying amounts (up to 60%) fromchicken and livestock sources. These results suggest thatantibiotic resistance patterns of FC may be used to determinesources of fecal contamination and aid in the direction ofwater quality improvement.     

Environmental Impact Assessment of the Mining and Concentration Activities in the Kola Peninsula, Russia by Multidate Remote Sensing

On the Kola Peninsula, the mining and concentration industry exerts anthropogenic impact on the environment. Tailing dumps cause airborne pollution through dusting, and waterborne pollution due to direct dumping and accidental releases. The objectives were: (1) to analyse multidate satellite imagesfor 1964–1996 to assess the environmental pollution from themining and concentration activity in the Kola in temporal perspective; (2) to evaluate remote sensing methods for integrated environmental impact assessment. The area of mining and industrial sites steadily expands and amounted to 94 km² in 1996. The polluted water surface amounted to at least 150 km² through dumping in 1978 and to 106 km² in1986 due to dusting. Thus, the impact from the mining and concentration activity should be reconsidered as more significant than it was officially anticipated. In the past the main mechanism of pollution wasdirect dumping into the lakes. Currently and in future, airborne pollution after dusting storms will dominate. The effective recultivation of the tailing dumps will be a long-term process. For effective assessment of impacts from the mining and concentration industry, remote sensing methods should be complemented by in-situ measurements, fieldwork, and mathematical modelling.     

Chemistry of Dissolved Organic Carbon at Bear Brook Watershed, Maine: Stream Water Response to (NH4)2SO4 Additions

This study was conducted to determine the response of stream water DOC and organic acidity to increased inputs of ammonium sulfate to a whole catchment. Precipitation, throughfall, soil solutions (from Spodosols) and stream waters were characterized for DOC concentrations and fractions (hydrophobic acids and neutrals, hydrophilic acids, bases, and neutrals) in both the control (East Bear) and the treatment (West Bear) catchments of Bear Brook Watershed, Maine (BBWM), a northern hardwood forest. In all solutions except precipitation, DOC was composed primarily of organic acids, with hydrophobic acids dominating (> 60% of DOC) in forest floor leachates (5000 mol C L-1), and a balance of hydrophobic and hydrophilic acids in deep B horizons and stream waters ( 150 mol C L-1). Stream waters had higher concentrations of DOC during storm or snowmelt events (high discharge), often reaching 300 to 400 mol C L-1. Forest floor leachate C was rapidly attenuated by the mineral soils under all flow conditions, indicating how important mineral soil sorption of DOC was in reducing the loss of C via surface water from BBWM. No differences occurred between control and treatment streams for concentration or composition of DOC due to treatment from 1989 through 1994. In 1995, West Bear Brook had much lower concentrations of DOC than East Bear for the first time. However, this occurred during a year of record low runoff, suggesting that hydrology may have affected export of C. Average annual export of DOC from the catchments was similar (1000 to 2000 mol C ha-1 yr-1). Organic anions in streamwaters increased slightly during high flow events (e.g., East Bear had means of 15 and 19 eq L-1 organic anions during base flow and high discharge in 1995). Treatment of West Bear caused a decrease in organic anions, both in concentration and contribution to overall anion composition (organic anions during high discharge as a percentage of total anions decreased from about 8 to 4% for 1987-89 and 1993-95 samples, respectively). This was probably due to decreased solution pH (greater protonation of organics) and higher concentrations of inorganic anions. Overall, there were no clear, detectable changes in stream water DOC, with only minor changes in organic anions, as a result of treatment with ammonium sulfate.     

The effect of temperature and salinity on copper body-burden and copper toxicity to Hediste (Nereis) diversicolor

Temperature from 12 to 22°C and salinity from 30.5 to 7.6 increased accumulation of copper in Hediste diversicolor. Copper accumulated ranged from 85.83 to 217.14 g g^-1. Sediments reduced accumulation of copper under temperature-salinity combinations. Accumulated copper ranged from 90.19 to 153.26 g g^-1.However, mortality of the worms was not solely dependent upon copper body-burden. It ranged from 34 to 45% and from 38 to 80% in the presence of sediment. A combination of osmoregulatory and thermal stresses increased the toxic effect of copper to the worms.     

Intake of Chromium by the Adult Population of Mumbai City

Electro Thermal Atomic Absorption Spectrophotometry (ET-AAS), is used for the determination of chromium (Cr) in a variety of environmental matrices. The detection limit for the estimation of Cr is 2 pg absolute for a volume injection of 20 l. The precision of the method is established by analysing Cr from a synthetic mixture containing various elements in different qualities (0.5–10 ppm) and is found to be within ± 8%. The reliability of estimation is further assessed through the analysis of Standard Reference Materials (SRMs) of soil, hay, milk powder and lake sediment obtained from IAEA.The total intake of Cr through air, water and food works out to be 54 g/day for the adult population of Mumbai city. The dietary intake through food is the major contributor to the total intake of Cr. The concentration of Cr in atmospheric air and drinking water collected from different suburbs showed geometric mean concentrations of 0.09 g/m³ and 0.3 g/l, respectively. The daily intake of Cr, though lower, is closer to the lower bound of the recommended value of 50–200 g/day.