Evaluation Of Ambient Air Pollution Impact On Carrot Plants At A Sub Urban Site Using Open Top Chambers

The present experiment was done to evaluate the impact of ambient air pollution on carrot (Dacus carotavar. Pusa Kesar) plants using open top chambers (OTCs) ventilated with ambient (NFCs) or charcoal filtered air (FCs) at a suburban site of Varanasi, India. Various morphological, physiological and biochemical characteristics of the plants were studied at different growth stages. Air monitoring data clearly showed high concentrations of SO₂, NO₂and O₃in the ambient air of study site. SO₂and NO₂concentrations were higher during early growth stages of carrot, whereas O₃concentration was highest during later growth stages. Filtration of air has caused significant reductions in all the three pollutant concentrations in FCs as compared to NFCs.Plants growing in FCs showed significantly higher photosynthetic rate, stomatal conductance, water use efficiency and variable fluorescence as compared to plants growing in NFCs. Protein content also showed a similar pattern, however, lipid peroxidation, ascorbic acid content and peroxidase activity were higher in plants growing in NFCs as compared to FCs. Shoot length, number of leaves per plant, leaf area and root and shoot weight increased significantly upon filtration of ambient air. Total nitrogen decreased significantly in root, but increased significantly in shoot of plants grown in NFCs. Total P, Mg, Ca and K contents decreased significantly in plants grown in NFCs as compared to FCs. The individual pollutant concentrations were below threshold for plant injury, but the combined effect of all the three seems to act synergistically in causing greater adverse impact on dry weight and physiology of carrot plants. The study clearly indicates that air pollutants are high enough in the ambient air to cause significant unfavorable impact on carrot plants. The work further supports the usefulness of OTCs for assessing air pollution damage under field conditions in developing countries.     

Ambient hydrogen sulphide levels at a wastewater treatment plant

This paper describes a novel technique of measuring ambient hydrogen sulphide (H₂S) concentrations simultaneously at several locations around a wastewater treatment plant. A commercially purchased H₂S monitor is modified to operate in a static mode to enable degree of darkening on pieces of lead acetate tapes to be correlated againts the exposure duration and the ambient H₂S concentration of sewage air. The technique can yield mapped contours of time—average H₂S concentrations as low as 0.2 ppm. The methodology is exemplified for a wastewater treatment plant in Ipswich, Queensland. Isopleths of H₂S concentration obtained at the wastewater site for two different meteorological conditions reveal that high levels of H₂S are detected around the plant's inlet structure and primary clarifiers.     

An implementation plan for using biological indicators to improve assessment of water quality in Thailand

The present study showed a possibility to use phenotypic and proteomic responses in rice plants as an in vivo biomarker to detect higher concentrations of ambient ozone (O₃). The investigation was done on two cultivars of Indian rice using open top chambers ventilated with charcoal filtered air, ambient air, ambient air with 10 ppb O₃ exposure and ambient air with 20 ppb O₃ exposure at a rural site of Varanasi, India. Results showed that the magnitude of O₃ induced specific type of foliar injury directly depends on the duration and concentration of O₃ exposure. Even the internal protein profile of injured and normal leaf demonstrated a differential expression, which directly indicates towards the molecular basis of plant’s response against O₃.     

An assessment of air quality in Karachi,Pakistan

An atmospheric pollution survey was carried out at 13 sites in Karachi, Pakistan, simultaneously from 0600 h to 2100 h for 15 consecutive days in May 1990 which also included meteorological measurements. The monitoring sites were included along the prevailing wind patterns in Karachi. Carbon monoxide levels in the ambient air were found to reach 9–10 ppm along the busy urban streets whereas CO₂ level exceeded 370 ppm in these areas. Our survey indicates that NO₂ levels were exceeding U.S. ambient air quality standards. Maxmum NO₂ concentrations were observed (0.3–0.5 ppm) during the daytime from 0600 h to 2100 h. The surface ozone maximum around noon at the inland sites reached the levels of 40 ppb and 50 ppb respectively compared to upwind coastal Sites 1 level of 25 ppb. The Pb concentrations were approximately 3- to 7-fold higher than average, which corresponded well to urban air. Fossil fuel SO₄ (excess) and NO₃ were apportionally based on the assumption that these two anions were present as (NH₄)₂SO₄, and NH₄NO₃ in the aerosols. In the eastern part of the city atmospheric sulphate (SO₄) shows the combustion of coal as its source from the vicinity and downwind of a steel manufacturing plant.     

Particulate matter concentration in ambient air and its effects on lung functions among residents in the National Capital Region, India

The World Health Organization has estimated that air pollution is responsible for 1.4 % of all deaths and 0.8 % of disability-adjusted life years. NOIDA, located at the National Capital Region, India, was declared as one of the critically air-polluted areas by the Central Pollution Control Board of the Government of India. Studies on the relationship of reduction in lung functions of residents living in areas with higher concentrations of particulate matter (PM) in ambient air were inconclusive since the subjects of most of the studies are hospital admission cases. Very few studies, including one from India, have shown the relationship of PM concentration and its effects of lung functions in the same location. Hence, a cross-sectional study was undertaken to study the effect of particulate matter concentration in ambient air on the lung functions of residents living in a critically air-polluted area in India. PM concentrations in ambient air (PM_1, PM_2.5) were monitored at residential locations and identified locations with higher (NOIDA) and lower concentrations (Gurgaon). Lung function tests (FEV₁, PEFR) were conducted using a spirometer in 757 residents. Both air monitoring and lung function tests were conducted on the same day. Significant negative linear relationship exists between higher concentrations of PM₁ with reduced FEV₁ and increased concentrations of PM_2.5 with reduced PEFR and FEV₁. The study shows that reductions in lung functions (PEFR and FEV₁) can be attributed to higher particulate matter concentrations in ambient air. Decline in airflow obstruction in subjects exposed to high PM concentrations can be attributed to the fibrogenic response and associated airway wall remodeling. The study suggests the intervention of policy makers and stake holders to take necessary steps to reduce the emissions of PM concentrations, especially PM_1, PM_2.5, which can lead to serious respiratory health concerns in residents.     

Characterization of ambient ozone and its precursors around a coking plant

The local-scale relationship between ambient ozone (O₃) and its precursors was examined around a coking plant in northern China. The upwind, plant boundary, and downwind locations were selected for investigation during the summer and autumn seasons in 2012. It was found that propene, toluene, and benzene were the top three non-methane hydrocarbon (NMHC) species for O₃ formation at plant boundary, while propene, toluene, and m/p-xylene were the top three NMHC species at downwind location. Isoprene was the dominant species for O₃ formation at upwind location. It was also found that an O₃ depressing process occurred at plant boundary as a result of high NO emissions. Both local photochemistry and transport led to O₃ accumulation at the downwind locations. The variation of NMHC concentration during O₃ polluted and non-polluted episodes was investigated, and it indicated that NMHC concentration was higher during non-polluted episodes than polluted episodes. The impacts of precursors on O₃ formation under different meteorological conditions were also examined.     

A new indicator of fireworks emissions in Rochester, New York

In ambient particle source apportionment studies, data for holidays such as July 4 (US Independence Day) are normally removed because of the high concentrations of chemical species and unusually high particle mass concentrations that are due to fireworks. Many cultures celebrate events with fireworks. A near real-time measurement that could indicate fireworks would be useful in indicating their impact on air quality. Commonly monitored ambient pollutants include PM_2.5, CO, SO₂, O₃, 10–500-nm particle number, and black carbon (BC). Using a two-wavelength aethalometer, another parameter, delta-C (UVBC_370?nm–BC_880?nm, aethalometer), can be calculated. These variables were continuously monitored during July 1–7, 2005–2010, in Rochester, New York. High delta-C values are normally associated with biomass combustion particles. However, statistically higher delta-C values were observed on Independence Day compared to the other period. Back trajectory analysis showed transport of local fireworks smoke to the sampling site on the night of July 4. An enhanced correlation between delta-C and BC during the fireworks episodes suggests changes from the usual BC sources. Fireworks emissions changed the ambient carbonaceous particulate species during these intervals. The delta-C value was found to be a readily measured indicator of fireworks emissions during periods when wood combustion was not likely to be present and provides a tool for monitoring such emissions where they might be more common such as amusement parks.     

Heavy metals in urban ambient PM10 and soil background in eight cities around China

The ambient PM₁₀ and background soil samples were collected and analyzed with ICP-AES in eight cities around China to investigate the levels of ten heavy metals (Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, and Pb). The mean concentrations of ten heavy metals in PM₁₀ of the eight cities of China followed the order of Zn?>?Pb?>?Mn?>?Cu?>?Ni?>?Cr?>?Co?>?V. The metals in the ambient PM₁₀ and soil were compared in each city to evaluate the heavy metal mass fraction from anthropogenic sources in ambient air. The CD values in these cities were all above 0.2, indicating that the ingredients spectrums of PM₁₀ and soil vary markedly. Most heavy metals were enriched in PM₁₀, except Fe and Ti. The results showed that almost all the cities suffer important heavy metal pollution from anthropogenic sources. The eight cities were also grouped according to their similarity in heavy metals of ambient PM₁₀ by cluster analysis to investigate the relationship between the heavy metals and the pollution sources of each city. The conclusion was that the eight cities were divided into three clusters which had similar industrial type and economy scale: the first cluster consisted of Shenzhen, Wuxi, and Guiyang; followed by Jinan and Zhengzhou as the second grouping; and the third group had Taiyuan, Urumqi, and Luoyang.     

Diurnal concentrations variations,size distributions for ambient air particles and metallic pollutants (Cr,Mn, Ni,Cd, Pb) during summer season at a traffic area

This study characterized and discussed particulate ambient air particulate concentrations and seasonal variations for PM₁₈, PM₁₀, PM_2.5, and PM₁ during June 2013–July 2013 at this traffic sampling site. In addition, this study also characterized the ambient air particulates size distributions by using MOUDI-100S4 sampler to collect 1-day the ambient suspended particles (PM₁₈, PM₁₀, PM_2.5, and PM₁) at this sampling site. In addition, the study also showed that the main pollutants contributions were from traffic and residual areas. As for the pollutants seasonal concentrations variations, the results indicated that the average particle concentrations orders were all displayed as daytime?>?nighttime for PM₁₈, PM₁₀, PM_2.5 and PM₁ at this characteristic sampling site. The results further indicated that the mean highest of metal concentrations in this study indicated that the average metal concentration were all displayed as Mn?>?Cr?>?Ni?>?Pb?>?Cd for PM₁₈, PM₁₀, PM_2.5 and PM₁ on daytime and nighttime at this characteristic sampling site.     

Occurrence, distribution, and source of polybrominated diphenyl ethers in soil and leaves from Shenzhen Special Economic Zone, China

Polybrominated diphenyl ethers (PBDEs) were measured in soil and three plant species samples taken at different land use areas in Shenzhen China. The concentrations of ??₇BDEs (BDE-28, BDE-47, BDE-99, BDE-100, BDE-153, BDE-154, and BDE-183) and BDE-209 in the surface soils ranged from 0.23 to 271 and 8.9 to 5,956 ng/g dry weight (dw), respectively. These figures are comparable to that in the soils of electronic waste dismantling sites. BDE-209 was the predominant congener (contributes 85?C99% of ??₈PBDEs (??₇PBDEs plus BDE-209)) in soils. The regression slopes of total organic carbon and individual BDE congeners were rather gentle, indicating that factors other than soil organic matter regulated the soil concentrations. Proximity to sources of deposition processes might be the major factors. In the plant leaves, ??₇BDEs and BDE-209 concentrations ranged from 1.29 to 5.91 and 5.49 to 28.2 ng/g dw, respectively. BDE-209 is also the dominant component, but the contribution was much lower compared with that in soils. Bauhinia purpurea Linn. and Michelia alba DC. show some similarities on the uptake of PBDEs, while Ficus microcarpa var. pusillifolia is different from them. The correlations between plant leaf concentrations and predicted gaseous concentrations were moderate, indicating that gaseous concentration did not influence the leaf concentration significantly.     

Emissions of SO2, NO x and particulates from a pipe manufacturing plant and prediction of impact on air quality

Integrated pipe manufacturing industry is operation intensive and has significant air pollution potential especially when it is equipped with a captive power production facility. Emissions of SO₂, NO _x , and particulate matter (PM) were estimated from the stationary sources in a state-of-the-art pipe manufacturing plant in India. Major air polluting units like blast furnace, ductile iron spun pipe facility, and captive power production facility were selected for stack gas monitoring. Subsequently, ambient air quality modeling was undertaken to predict ground-level concentrations of the selected air pollutants using Industrial Source Complex (ISC 3) model. Emissions of SO₂, NO _x , and particulate matter from the stationary sources in selected facilities ranged from 0.02 to 16.5, 0.03 to 93.3, and 0.09 to 48.3 kg h^???1, respectively. Concentration of SO₂ and NO _x in stack gas of 1,180-kVA (1 KW = 1.25 kVA) diesel generator exceeded the upper safe limits prescribed by the State Pollution Control Board, while concentrations of the same from all other units were within the prescribed limits. Particulate emission was highest from the barrel grinding operation, where grinding of the manufactured pipes is undertaken for giving the final shape. Particulate emission was also high from dedusting operation where coal dust is handled. Air quality modeling indicated that maximum possible ground-level concentration of PM, SO₂, and NO _x were to the tune of 13, 3, and 18 μg/m³, respectively, which are within the prescribed limits for ambient air given by the Central Pollution Control Board.     

An evaluation of improvements in the air quality of Beijing arising from the use of new vehicle emission standards

An innovative approach of mean emission by vehicle type was used in this paper to assess the impact of new vehicle emission standards in Beijing, China during the period of 2000–2005. It was found that CO and NO_x emissions decreased by 48% and 23%, respectively, from Type O (before 2000) to Type I (year 2000) vehicles. The reductions from Type O to Type II (year 2002) vehicles were 85% and 73% for CO and NO_x, respectively. When all three types of vehicles (Types O, I and II) are combined, the annual per vehicle CO emissions decreased from 586 kg per vehicle per year in 2000 to 324 kg per vehicle per year in 2005, while that of NO_x decreased from 66.9 to 43.4 kg per vehicle per year, which was mainly resulted from the impact of stringent new vehicle emission standards implemented in years 2000 and 2002. However, the vehicle population increased by 70% during the same time period, which offset the impact of cleaner vehicles. Thus, the total vehicle emission decreased little for CO (885,000 tons in 2000, 837,000 tons in 2005) and even increased slightly for NO_x (101,000 and 112,000 tons in 2000 and 2005, respectively). The ambient concentrations of CO decreased significantly throughout 2000–2005, the same trend was not observed for NO₂. Correlation analysis (grey correlation and Pearson correlation) between the annual vehicle emissions and annual concentrations of CO, the annual NO_x emission and annual NO₂ concentration indicated that the implementation of new vehicle emission standards was associated with the abatement of ambient CO and NO₂ concentrations in Beijing.     

Local Air Quality Impacts due to Downwash Around Thermal Power Plants: Numerical Simulations of the Effect of Building Orientation

One of the primary adverse environmental impacts associated with power generation facilities and in particular thermal power plants is local air quality. When these plants are operated at inland areas the dry type cooling towers used may significantly increase ambient concentrations of air pollutants due to the building downwash effect. When one or more buildings in the vicinity of a point source interrupt wind flow, an area of turbulence known as a building wake is created. Pollutants emitted from relatively low level sources can be caught in this turbulence affecting their dispersion. In spite of the fact that natural gas-fired combined-cycle power plants have lower air emission levels compared to other power plants using alternative fossil fuel, they can still create significant local air pollution problems. In this paper, local air quality impacts of a natural gas-fired combined-cycle power plant located in a coastal area are compared with those of another natural gas-fired combined-cycle power plant having identical air emissions but located in an inland area taking into account differences in topography and meteorology. Additionally, a series of scenarios for the inland site have been envisaged to illustrate the importance of plant lay-out configurations paying particular attention to the building downwash effect. Model results showed that different geometrical configurations of the stacks and cooling towers will cause remarkable differences in ambient air pollutant concentrations; thus it is concluded that when selecting a plant site, a detailed site-specific investigation should be conducted in order to achieve the least possible ambient air pollution concentrations with the given emissions.     

Characterization and Identification of the Sources of Chromium, Zinc, Lead, Cadmium, Nickel, Manganese and Iron in Pm10 Particulates at the Two Sites of Kolkata, India

Monitoring of ambient PM₁₀ (particulate matter which passes through a size selective impactor inlet with a 50% efficiency cut-off at 10 μm aerodynamic diameter) has been done at residential (Kasba) and industrial (Cossipore) sites of an urban region of Kolkata during November 2003 to November 2004. These sites were selected depending on the dominant anthropogenic activities. Metal constituents of atmospheric PM₁₀ deposited on glass fibre filter paper were estimated using Inductively Coupled Plasma Atomic Emission Spectrometer (ICP-AES). Chromium (Cr), zinc (Zn), lead (Pb), cadmium (Cd), nickel (Ni), manganese (Mn) and iron (Fe) are the seven toxic trace metals quantified from the measured PM₁₀ concentrations. The 24 h average concentrations of Cr, Zn, Pb, Cd, Ni, Mn and Fe from ninety PM₁₀ particulate samples of Kolkata were found to be 6.9, 506.1, 79.1, 3.3, 7.4, 2.4 and 103.6 ng/m³, respectively. The 24 h average PM₁₀ concentration exceeded national ambient air quality standard (NAAQS) as specified by central pollution control board, India at both residential (Kasba) and industrial (Cossipore) areas with mean concentration of 140.1 and 196.6 μg/m³, respectively. A simultaneous meteorology study was performed to assess the influence of air masses by wind speed, wind direction, rainfall, relative humidity and temperature. The measured toxic trace metals generally showed inverse relationship with wind speed, relative humidity and temperature. Factor analysis, a receptor modeling technique has been used for identification of the possible sources contributing to the PM₁₀. Varimax rotated factor analysis identified four possible sources of measured trace metals comprising solid waste dumping, vehicular traffic with the influence of road dust, road dust and soil dust at residential site (Kasba), while vehicular traffic with the influence of soil dust, road dust, galvanizing and electroplating industry, and tanning industry at industrial site (Cossipore).     

Assessment of Ambient Air Quality in Urban Centres of Haryana (India) in Relation to Different Anthropogenic Activities and Health Risks

Considering the mounting evidences of the effects of air pollution on health, the present study was undertaken to assess the ambient air quality status in the fast growing urban centres of Haryana state, India. The samples were collected for total suspended particulate matter (TSPM), respirable suspended particulate matter (PM₁₀), sulfur dioxide (SO₂), and oxides of nitrogen (NO₂) during different seasons from 8 districts of Haryana during January, 1999 to September, 2000. The four types of sampling sites with different anthropogenic activities i.e. residential, sensitive, commercial and industrial were identified in each city. The ambient air concentration of TSPM and PM₁₀ observed was well above the prescribed standards at almost all the sites. The average ambient air concentrations of SO₂ and NO₂ were found below the permissible limits at all the centres. Comparatively higher concentration of SO₂ was observed during winter seasons, which seems to be related with the enhanced combustion of fuel for space heating and relatively stable atmospheric conditions. Air Quality Index (AQI) prepared for these cities shows that residential, sensitive and commercial areas were moderately to severely polluted which is a cause of concern for the residents of these cities. The high levels of TSPM and SO₂ especially in winter are of major health concern because of their synergistic action. The data from Hisar city reveals a significant increase in the total number of hospital visits/admissions of the patients with acute respiratory diseases during winter season when the level of air pollutants was high.     

基于区域环境空气质量和碳排放数据的减污降碳协同效果评估

化石燃料燃烧产生的温室气体与大气污染物具有同根同源性,但具体治理中减污降碳的协同效果尚不明确。以浙江省11个设区市为研究样本,对环境空气质量和二氧化碳(CO₂)排放数据进行分析研究,结果显示：2016—2020年浙江省环境空气质量持续改善,但CO₂排放总量仍处于增长阶段。11个设区城市PM_2.5年均浓度降幅在26%～41%之间,二氧化氮(NO₂)年均浓度下降趋势不明显,大部分城市呈现碳排放增加、NO₂浓度下降的特征,只有杭州和温州两市呈现碳排放总量和NO₂、PM_2.5浓度协同下降的趋势。因子相关性分析结果表明,各设区市呈现NO₂浓度与碳排放相关性较大、协同性强,PM_2.5浓度与碳排放相关性较小的特点。进一步通过减污降碳协同定量评价分析表明,浙江地区在环境空气质量改善和温室气体减排已表现出一定成效,但各设区市因产业结构、环境基础条件、协同程度等不同导致减污降碳综合绩效有明显差异。从源头减排实现...     

Air Pollution Concentrations of PM2.5, PM10 and NO2 at Ambient and Kerbsite and Their Correlation in Metro City – Mumbai

Ambient concentrations of PM_2.5 and PM₁₀ are of concern with respect to effects on human health and environment. Increased levels of mortality and morbidity have been associated with respirable particulate air pollution. In India, it is not yet mandatory to monitor PM_2.5 levels therefore very limited information is available on PM_2.5 levels. To understand the fine particle pollution and also correlate with PM₁₀ which are monitored regularly in compliance with ambient air quality standards. This study was carried out to monitor PM_2.5, PM₁₀, and NO₂ for about one year in a residential cum commercial area of Mumbai city with a view to understand their correlation. The average PM_2.5 concentration at ambient and Kerbsite was 43 and 69 μg/m³. The correlation coefficients between PM_2.5 and PM₁₀ at ambient and Kerbsite were 0.83 and 0.85 respectively thus indicating that most of the PM_2.5 and PM₁₀ are from similar sources. TSP, PM₁₀ levels exceeded Central Pollution Control Board(CPCB) standard during winter season. PM_2.5 levels also exceeded 24 hourly average USEPA standard during winter season indicating unhealthy air quality.     

Study of temporal variation in ambient air quality during Diwali festival in India

The variation in air quality was assessed from the ambient concentrations of various air pollutants [total suspended particle (TSP), particulate matter ≤10 μm (PM₁₀), SO₂, and NO₂] for pre-Diwali, Diwali festival, post-Diwali, and foggy day (October, November, and December), Delhi (India), from 2002 to 2007. The extensive use of fireworks was found to be related to short-term variation in air quality. During the festival, TSP is almost of the same order as compared to the concentration at an industrial site in Delhi in all the years. However, the concentrations of PM₁₀, SO₂, and NO₂ increased two to six times during the Diwali period when compared to the data reported for an industrial site. Similar trend was observed when the concentrations of pollutants were compared with values obtained for a typical foggy day each year in December. The levels of these pollutants observed during Diwali were found to be higher due to adverse meteorological conditions, i.e., decrease in 24 h average mixing height, temperature, and wind speed. The trend analysis shows that TSP, PM₁₀, NO₂, and SO₂ concentration increased just before Diwali and reached to a maximum concentration on the day of the festival. The values gradually decreased after the festival. On Diwali day, 24-h values for TSP and PM₁₀ in all the years from 2002 to 2007 and for NO₂ in 2004 and 2007 were found to be higher than prescribed limits of National Ambient Air Quality Standards and exceptionally high (3.6 times) for PM₁₀ in 2007. These results indicate that fireworks during the Diwali festival affected the ambient air quality adversely due to emission and accumulation of TSP, PM₁₀, SO₂, and NO_2.     

Air Quality Status of an Open Pit Mining Area in India

This investigation presents the assessment of ambient air quality carried out at an open pit coal mining area in Orissa state of India. The 24-h average concentrations of suspended particulate matter (SPM), respirable particulate matter (RPM, particles of less than 10 m aerodynamic diameter), sulphur dioxide (SO₂) and oxides of nitrogen (NO_x) were determined at regular interval throughout one year at 13 monitoring stations in residential area and four stations in mining/industrial area. During the study period, the 24-h and annual average SPM and RPM concentrations exceeded the respective standards set in the Indian ambient air quality standard (NAAQS) protocol in most of the residential and industrial areas. However, the 24-h and annual average concentrations of SO₂ and NO_x were well within the prescribed limit of the NAAQS in both residential and industrial areas. A management strategy is formulated for effective control of particulate matter at source and other mitigative measures are recommended including implementation of green belts around the sensitive areas.     

The Mid-Canada Radar Line and First Nations' people of the James Bay region, Canada: an evaluation using log-linear contingency modelling to analyze organochlorine frequency data

Abandoned radar line stations in the North American arctic and sub-arctic regions are point sources of contamination, especially for PCBs. Few data exist with respect to human body burden of organochlorines (OCs) in residents of communities located in close proximity to these radar line sites. We compared plasma OC concentration (unadjusted for total lipids) frequency distribution data using log-linear contingency modelling for Fort Albany First Nation, the site of an abandoned Mid-Canada Radar Line station, and two comparison populations (the neighbouring community of Kashechewan First Nation without such a radar installation, and Hamilton, a city in southern Ontario, Canada). This type of analysis is important as it allows for an initial investigation of contaminant data without imputing any values. The two-state log-linear model (employing both non-detectable and detectable concentration frequencies and applicable to PCB congeners 28 and 105 and cis-nonachlor) and the four-state log-linear model (using quartile concentration frequencies for Aroclor 1260, PCB congeners [99,118,138,153,156,170,180,183,187], beta-HCH, p,p'-DDT +p,p'-DDE, HCB, mirex, oxychlordane, and trans-nonachlor) revealed that the effects of subject gender were inconsequential. Significant differences (p < 0.05) between the groups examined were attributable to the effect of location on the frequency of detection of OCs or on their differential distribution among the concentration quartiles. In general, people from Hamilton had higher frequencies of non-detections and of concentrations in the first quartile (p < 0.05) for most OCs compared to people from Fort Albany and Kashechewan (who consume a traditional diet of wild meats that does not include marine mammals). An unexpected finding was that, for Kashechewan males, the frequency of many OCs was significantly higher (p < 0.05) in the 4th concentration quartile than that predicted by the four-state log-linear model, but significantly lower than expected in the 1st quartile for beta-HCH. The levels of PCBs found for women in Fort Albany and Kashechewan were greater than those reported for Dene (First Nation people) and Métis (mixed heritage) of the western Northwest Territories (NWT) who did not consume marine mammals, and for Inuit living in the central NWT (occasional consumers of marine mammals). Moreover, the levels of total p,p'-DDT were greater for Fort Albany and Kashechewan women compared to these same aboriginal groups.