Effects of smoking on the levels of urinary biomarkers of aromatic hydrocarbons in oil refinery workers

Occupational exposures to aromatic hydrocarbons may be overwhelmed by mainstream and secondary smoking exposures. The objective of this study was to evaluate the influence of occupational exposures and smoking on benzene and toluene urinary metabolites. The metabolites were measured in pre and post-work shift urine specimens in oil refinery workers by gas chromatography/mass spectrometry techniques. Post-shift concentration differences between non-smokers and smokers were statistically significant (at p-value?<?0.05). Pre- and post-shift concentrations of urinary phenol (benzene biomarker) did not vary significantly for both non-smokers and smokers. Occupational exposures to toluene triggered an increase of post-shift levels (compared to pre-shift levels) of urinary cresol for non-smokers and workers who had less than 10 cigarettes during the work shift. For these groups, non-occupational exposures before and during the work shift did not vary. For smokers who did not smoke during the work shift and for those who had more than ten cigarettes during the shift, the post-shift levels of both cresol and hippuric acid were reduced approximately 30% lower than pre-shift levels. This is due to increased exposures to tobacco smoke before the work shift. The relationships between phenol and (cresol?+?hippuric acid) levels for non-smokers and smokers indicated that elevated co-exposures due to smoking result in the reduction of all metabolites levels in urine. These findings demonstrated that exposures to tobacco smoke may stochastically interfere with occupational exposures when biological monitoring is used to assess occupational health risks. Factors influencing the magnitude of the interference were specimen collection time (in relation to the timing of occupational exposures and excretion rates of biomarkers), smoking intensity and timing before and during the work shift.     

Estimating cancer risk due to benzene exposure in some urban areas in Bangkok

Benzene exposure is of particular concern because recent research indicates that it can result in chronic toxicity, with an elevated risk of carcinogenesis. Exposure to benzene from automobile exhaust can be an important occupational problem for urban population. The present study was conducted to estimate cancer risk of population living in nine densely traffic jam area due to contact with traffic benzene vapor during daily work. The reported lifetime unit risk factor ranges from 8.30E-8 to 1.58E-6. Of interest, this number is high and can be important public health threaten. Monitoring of environmental benzene can help classify with high risk. Annual check up and monitoring for benzene exposure among the people living in urban area should be set as primary prevention of benzene-related cancer for them.     

A method of urban ecological risk assessment: combining the multimedia fugacity model and GIS

Industrial pollution has caused serious human health risk because the pollutants can be accumulated in human body via multi routes in a long term, especially in areas of rapid industrialization. It is of great importance to obtain the pollutants’ information, including the transport routes and spatial distribution in the various environmental media of different sub-regions, to facilitate more accurate risk assessment and more effective risk management in urban ecosystems. In this article, we proposed a research framework of urban ecological risk assessment method, which combines the multimedia fugacity model, the multi-route exposure model, exposure-risk relationships and geographic information system (GIS). An urban ecological risk assessment of a hypothetical region indicates that it is possible and feasible to introduce GIS into the previous method to satisfy the requirements of risk management. The assessment results can be further utilized for industrial pollution emission control.     

Monitoring de la Pollution Atmosphérique au-dessus d'un Site Urbain par mesures Lidar

We have used a ruby Lidar to study the space and time variations of atmospheric aerosols on a horizontal level above a town site. It has allowed us to locate the main sources of industrial pollution and to evaluate the amplitude of retrodiffusion signals due to the town activity.We have demonstrated the influence of the winds whose speed is higher than 3 m/s. We have observed that at any particular place in the town the ratio Am/Amo varied from 1 to 14, this radio characterizing the concentration in pollutants above a place in the town (Am is the amplitude of the retrodiffusion Lidar signal, Amo is the echo lidar amplitude characterizing the average noise of the urban site).     

福建闽江水口库区飘浮植物覆盖对水体环境的影响

为了探索城市富营养化湖泊生态修复技术,2000年9月在南京市莫愁湖物理生态工程试验区内,开展了隔离外源污染、覆盖底泥和种植水生植物对湖泊水质平均水平和水体脉动强度影响的比较研究．试验结果表明,通过围隔隔离外源污染可在较短时间内迅速改善湖泊TN的平均水平,但难以提高湖泊生态系统的稳定性;通过覆盖底泥控制内源污染难以改善湖泊水质的平均水平,并且难以提高湖泊生态系统的稳定程度;种植水生植物不仅能够全面改善湖泊水质的平均水平,而且可以提高湖泊生态系统的稳定性．此外,富营养化湖泊中,藻类生长与湖水营养盐浓度并不存在正相关的关系．因此,对城市湖泊富营养化的防治,在控制外源污染降低营养盐浓度的同时,应恢复湖泊原有的以水生高等植物为主的生态系统．     

Chemical composition and photochemical reactivity of exhaust from aircraft turbine engines

Assessment of the environmental impact of aircraft emissions is required by planners and policy makers. Seveal areas of concern are: 1. exposure of airport workers and urban residents to toxic chemicals emitted when the engines operate at low power (idle and taxi) on the ground; 2. contributions to urban photochemical air pollution of aircraft volatile organic and nitrogen oxides emissions from operations around airports; and 3. emissions of nitrogen oxides and particles during high-altitude operation. The environmental impact of chemicals emitted from jet aircraft turbine engines has not been firmly established due to lack of data regarding emission rates and identities of the compounds emitted. This paper describes an experimental study of two different aircraft turbine engines designed to determine detailed organic emissions, as well as emissions of inorganic gases. Emissions were measured at several engine power settings. Measurements were made of detailed organic composition from C₁ through C₁₇, CO, CO₂, NO, NO _x , and polycyclic aromatic hydrocarbons. Measurements were made using a multi-port sampling pro be positioned directly behind the engine in the exhaust exit plane. The emission measurements have been used to determine the organic distribution by carbon number and the distribution by compound class at each engine power level. The sum of the organic species was compared with an independent measurement of total organic carbon to assess the carbon mass balance. A portion of the exhaust was captured and irradiated in outdoor smog chambers to assess the photochemical reactivity of the emissions with respect to ozone formation. The reactivity of emissions from the two engines was apportioned by chemical compound class.     

韧性城市的研究进展和韧性城乡建设的建议

城市的安全稳定、美丽宜居和可持续发展是人类对城市发展的美好追求。韧性城市理念的孕育和产生是城市在漫长发展的历史中,逐步产生和形成的城市公共安全治理的重要途径和全新理念,对城市的建设和发展至关重要,近年来受到科技界的广泛关注。本文系统地梳理了当前有关韧性城市的研究成果;追溯了韧性城市理念的起源;全面地总结了不同学者和有关国际组织关于韧性城市定义和内涵的研究成果,给出了韧性城市新的定义;总结并归纳了韧性城市的主要特征、评价指标及方法;评述了韧性城市研究领域的最新研究进展;提出了我国开展韧性城乡建设的建议。本文的工作对从事韧性城市研究的科技工作者具有参考价值,对推动韧性城市建设及理论研究有重要意义。     

Assessing sound exposure from shipping in coastal waters using a single hydrophone and Automatic Identification System (AIS) data

Underwater noise from shipping is a growing presence throughout the world's oceans, and may be subjecting marine fauna to chronic noise exposure with potentially severe long-term consequences. The coincidence of dense shipping activity and sensitive marine ecosystems in coastal environments is of particular concern, and noise assessment methodologies which describe the high temporal variability of sound exposure in these areas are needed. We present a method of characterising sound exposure from shipping using continuous passive acoustic monitoring combined with Automatic Identification System (AIS) shipping data. The method is applied to data recorded in Falmouth Bay, UK. Absolute and relative levels of intermittent ship noise contributions to the 24-h sound exposure level are determined using an adaptive threshold, and the spatial distribution of potential ship sources is then analysed using AIS data. This technique can be used to prioritize shipping noise mitigation strategies in coastal marine environments.     

Cancer risk estimation from dietary arsenic,a new approach from longitudinal cohort study

Inorganic arsenic is a carcinogen and consumption in low dose may lead to cancer. We estimated the cancer risk of the participants from arsenic endemic regions of West Bengal, India. The probable cancer risk was estimated following the assessment of daily inorganic arsenic intake through drinking water and diets of 20 participants for three consecutive years who had been using low arsenic water in the Indian context (median arsenic concentration in the study Years-I, II and III were 22, 16, 13 µg/l respectively). Probable cancer risk of the population was 2.80 × 10^?4, 2.94 × 10^?4, 3.12 × 10^?4 in the three respective study years (Year-I, II and III); just higher than the US EPA risk level of concern. The arsenic species content of the paired raw, cooked rice and urine was estimated in the as is taken basis. The major diet component, rice contained 72–86% inorganic arsenic whereas urine contains 70% organic arsenic on an average. The cancer risk assessment has been proposed to be modified by inclusion of urine arsenic release, considering the fact of arsenic release through urine. The risk became 1.28 × 10^?5, 1.13 × 10^?5, 1.01 × 10^?5 in the study Year-I, II and III respectively, considering urinary arsenic release, attributed the consideration of urine arsenic release into probable cancer risk estimation.     

Variations in trace gas concentrations in different environments in India

Observations of trace gases (SO₂, NH₃, NO₂ and O₃) were made during the period 1981 to 1984 at 6 different locations representative of urban industrial, urban, nonurban, thermal power plant and marine environment. Diurnal variations of the trace gases were studied in an urban environment. Except in the urban industrial environment, the concentration of NH₃ was found in the range of background values. Also, the average concentrations of NO₂ and O₃ at the different environments were in the order of background values. However, the concentrations of SO₂ were substantially higher by about 7 times, in urban industrial and thermal power plant environments. The diurnal variations of SO₂, NH₃ and NO₂ showed anitphase relationship with surface temperature at the urban environment station which is relatively free of industrial pollution. Discussion is centred on trace gas variations in different environments in India together with the values reported for various countries in the world.     

RISING GROUND WATER – PROBLEM OR RESOURCE?

Abstract. Ground water rising to within 6 m (20 feet) of average ground surface elevations in Louisville, Kentucky caused concern to municipal officials and building owners in the central urban area. An average rise of more than 11 m (35 feet) occurred between 1969 and 1980.
An evaluation of foundation conditions and structural configurations in central Louisville indicated rising ground water could create:
1. slight but significant possibilities of structural settlement problems;
2. high possibilities of damage to basement floors and walls; and
3. very high possibilities for disruption of utility conduits.
Efforts to determine the cause of this rise in ground-water level have focused on the historical relationships between ground-water levels, pumpage rates and precipitation values.
Historical data indicated that ground-water levels in a system undisturbed by man could reach ground surface elevations in central Louisville. Preliminary studies indicated a strong relation between average ground-water levels and changes in pumping rates and incident precipitation. A further detailed study showed extremely high correlation (R = 0.995) between average ground-water levels in 1966–1980 and cumulative departures in precipitation and pumping rates from 1950–1965 average precipitation and pumping rates.
A study of the feasibility of lowering ground-water levels while simultaneously storing energy in the aquifer system was begun but was interrupted by devastating explosions of hexane in the sewers beneath south-central Louisville on February 13, 1981. Although a dry year in 1980 and no change in pumping rate have slowed the rise in ground-water level temporarily, long-term solutions to this problem need to be developed.     

Exposure reconstruction using a physiologically based toxicokinetic model with cumulative amount of metabolite in urine: a case study of trichloroethylene inhalation

The use of a physiologically based toxicokinetic (PBTK) model to reconstruct chemical exposure using human biomonitoring data, urinary metabolites in particular, has not been fully explored. In this paper, the trichloroethylene (TCE) exposure dataset by Fisher et al. (Toxicol Appl Pharm 152:339–359, 1998) was reanalyzed to investigate this new approach. By treating exterior chemical exposure as an unknown model parameter, a PBTK model was used to estimate exposure and model parameters by measuring the cumulative amount of trichloroethanol glucuronide (TCOG), a metabolite of TCE, in voided urine and a single blood sample of the study subjects by Markov chain Monte Carlo (MCMC) simulations. An estimated exterior exposure of 0.532 mg/l successfully reconstructed the true inhalation concentration of 0.538 mg/l with a 95% CI (0.441–0.645) mg/l. Based on the simulation results, a feasible urine sample collection period would be 12–16 h after TCE exposure, with blood sampling at the end of the exposure period. Given the known metabolic pathway and exposure duration, the proposed computational procedure provides a simple and reliable method for environmental (occupational) exposure and PBTK model parameter estimation, which is more feasible than repeated blood sampling.     

Assessment of genotoxic and humoral immune system alterations in silica exposed workers from pottery industries in South India

Chemicals, especially silica, have been suspected to cause genetic alterations in pottery industry workers. The present study aims to analyze the frequency of chromosomal aberrations (CA), micronucleus (MN) and DNA damage (comet assay) in the peripheral blood lymphocytes and the immunological alterations workers chronically exposed to silica and in control subjects. In our study, 50 silica exposed workers and 35 control subjects were recruited and silica level was measured by respirable dust and respirable quartz concentrations of badge dosimeter. The serum immunoglobulins (IgM, IgG, and IgA) of all the subjects were measured by using ELISA method. The individuals exposed to silica have a significant increase in the frequency of CA, MN and the total DNA damage (p < 0.05). Immunoglobulin elevation on silica exposed workers was statistically significant (p < 0.05) on comparison with their respective controls. Investigation of the smoking and alcohol habitats coupled with silica exposure in exposed and control subjects represents alcohol consumption and smoking as additional risk factors and must be avoided. Multiple linear regression analysis obtained for CA, MN and comet assay confirm these tests as biomarkers for silica exposed pottery workers. Some confounding factors also showed significant influence on exposed subjects. These results indicate the mutagenic risk in the working environment has a high probability of association with the silica dust exposure in pottery industries. Nevertheless, the present study will create awareness and public concern not only among the silica exposed workers but also to the welfare of their progeny.     

Ökologie des Aluminiums

After short introductory remarks about the general chemistry of Al, some chemical methods are outlined at first to investigate the speciation of Al in solution and in solids. Speciation, precipitation and complexation are of great importance for living organisms, both for aquatic and terrestric ones. Interactions between organic substances and Al-salts or Al-containing minerals are discussed for soil, freshwater and marine sediments. In plants, especially retardation of growth by available Al, mainly by shortening of roots, is looked upon in detail, because with regard to agriculture this is an important economical factor. Starting from chemical reactions at the molecular level, physiological changes and toxicity symptoms in animal cells can be understood; the severe neuronal damage is the most striking effect. Some aspects about the exposure of workers to Al-containing dusts are added.     

Metropolitan-scale Transport and Dispersion from the New York World Trade Center Following September 11, 2001. Part I: An Evaluation of the CALMET Meteorological Model

Following the collapse of the New York City World Trade Center towers on September 11, 2001, Local, State and Federal agencies initiated numerous air monitoring activities to better understand the impact of emissions from the disaster. A study of the estimated pathway that a potential plume of emissions would likely track was completed to support the U.S. EPA’s initial exposure assessments. The plume from the World Trade Center was estimated using the CALMET-CALPUFF dispersion modeling system. The following is the first of two reports that compares several meteorological models, including the CALMET diagnostic model, the Advanced Regional Prediction System (ARPS) and 5^th Generation Mesoscale Model (MM5) in the complex marine-influenced urban setting of NYC. Results indicate wind speed, in most cases, is greater in CALMET than the two mesoscale models because the CALMET micrometeorological processor does not properly adjust the wind field for surface roughness variations that exits in a major built-up urban area. Small-scale circulations, which were resolved by the mesoscale models, were not well simulated by CALMET. Independent wind observations in Lower Manhattan suggest that the wind direction estimates of CALMET possess a high degree of error because of the urban influence. Wind speed is on average 1.5 ms⁻¹ stronger in CALMET than what observations indicate. The wind direction downwind of the city is rotated 25–34 clockwise in CALMET, relative to what observations indicate.     

Geohazards due to technologically enhanced natural radioactive wastes

Human activities can modify naturally occurring radioactive material (NORM) into technologically enhanced naturally occurring radioactive material (TENORM) as a result of industrial activities. Most of these industries do not intend to work with radioactive material a priori. However, whenever a uranium- or thorium-bearing mineral is exploited, NORM-containing by-products and TENORM-contaminated wastes are created. The industrial use of NORM can result in non-negligible radiation exposure of workers and members of the public, exceeding by far the radiation exposure from nuclear technologies. For decades, millions of tons of NORM have been released into the environment without adequate control or even with the lack of any control. Various technologies have been developed for the control of NORM wastes. The paper discusses the merits and limitations of different NORM-waste management techniques, such as Containment, Immobilization, Dilution/Dispersion, Natural Attenuation, Separation, and - as an alternative - Cleaner Technologies. Each of these methods requires a comprehensive risk-benefit-cost analysis.     

Urban stormwater thermal gene expression models for protection of sensitive receiving streams

Thermal impact of typical high‐density residential, industrial, and commercial land uses is a major concern for the health of aquatic life in urban watersheds, especially in smaller, cold, and cool‐water streams. This is the first study of its kind that provides simple easy‐to‐use equations, developed using gene expression programming (GEP) that can guide the assessment and the design of urban stormwater management systems to protect thermally sensitive receiving streams. We developed 3 GEP models using data collected during 3 years (2009–2011) from 4 urban catchments; the first GEP model predicts event mean temperature at the inlet of the pond; the second model predicts the stormwater temperature at the outlet of the pond; and the third model predicts the temperature of the stormwater after flowing through a cooling trench and before discharging to the receiving stream. The new models have high correlation coefficients of 0.90–0.94 and low prediction uncertainty of less than 4% of the median value of the predicted runoff temperatures. Sensitivity analysis shows that climatic factors have the highest influence on the thermal enrichment followed by the catchment characteristics and the key design variables of the stormwater pond and the cooling trench. The general method presented here is easily transferable to other regions of the world (but not necessarily the exact equations developed here); also through sensitivity and parametric analysis, we gained insight on the key factors and their relative importance in modelling thermal enrichment of urban stromwater runoff.     

Levels and spatial distribution of heavy metals in urban dust in China

Many studies have been conducted on heavy metal concentrations in urban outdoor dust in China,showing that differences exist in the metal concentrations of different cities. However, no report has studied the distribution of heavy metals across Chinese cities. This work presents the spatial distribution of heavy metals in urban outdoor dust in Chinese cities and discusses the causes for the differences in heavy metal levels across cities by analyzing and summarizing data for 20 provincial capitals from the published scientific literature. The results show that the geometric mean values of Ni and Cr in urban dust of China are lower than or comparable to crustal levels, whereas levels of Cd, Cu, Pb, and Zn are significantly greater than crustal levels. The spatial distributions of Cu, Pb, and Zn in urban dust all exhibit a pattern in which heavy metal levels are greater in cities located in the south of China than in the north. Commercial areas and residential-education areas accumulate more Cd in their dust than industrial areas and traffic areas, and industrial areas and residential-education areas accumulate more Pb than commercial areas and traffic areas. The Zn level in dust from industrial areas is significantly greater than in other areas, and Cu exhibits no significant difference between different functional areas. A positive correlation exists between Cd and Zn in urban dust and population density. Urban dust Pb in Chinese cities is lower than the world average as calculated using data for thirteen cities in different countries. Cd, Cu, and Zn levels in China are close to world averages.     

Variations in racemization/epimerization ratios and amino acid content of Glycymeris shells in raised marine deposits in the Mediterranean

In this study we compare the organic geochemistry of fossil and modern Glycymeris shells. Amino acids were preserved within the shells. The amino acid content of the shells was similar at all the sites studied. Amino acid racemization and epimerization of Glycymeris shells are suitable techniques for dating Pleistocene raised marine deposits. As reported in other studies, we found that isoleucine epimerization analysis has a greater capacity to discriminate between sites of different age than glutamic acid and aspartic acid. However, particular constraints regarding the use of amino acid dating concern intrashell variability, so to avoid divergent results, it is necessary to sample the same part of the shell, namely the complex cross lamellar region near the umbo. The dating of high-energy coastal marine deposits calls for extensive field work in order to ensure the collection of a large number of samples in order to obtain robust results and reject spurious values. Shell accumulations on the shore-line are conditioned by several factors. The high coefficients of variation for epimerization values and their distribution pattern can be attributed mainly to time-linked taphonomical processes (time-averaging) that gave rise to the shell-bearing bed. However, reworking from former highstand sea level deposits, which usually occupy higher topographic levels, is not a common occurrence. Therefore, as a result of time-averaging and post-depositional processes, it is difficult to identify substages in stacked shell beds in raised beach deposits belonging to the same marine oxygen isotope stage by means of amino acid racemization/epimerization.     

Rapid tidal marsh development in anthropogenic backwaters

Tidal marsh restoration and creation is growing in popularity due to the many and diverse sets of services these important ecosystems provide. However, it is unclear what conditions within constructed settings will lead to the successful establishment of tidal marsh. Here we provide documentation for widespread and rapid development of tidal freshwater wetlands for a major urban estuary as an unintended result of early industrial development. Anthropogenic backwater areas established behind railroad berms, jetties, and dredge spoil islands resulted in the rapid accumulation of clastic material and the subsequent initiation of emergent marshes. In one case, historical aerial photos document this transition occurring in less than 18 years, offering a timeframe for marsh development. Accretion rates for anthropogenic tidal marshes and mudflats average 0.8–1.1 and 0.6–0.7 cm year⁻¹, respectively, equivalent to two to three times the rate of relative sea level rise as well as the observed accretion rate at a 6000+ year-old reference marsh in the study area. Paired historical and geospatial analysis revealed that more than half of all the tidal wetlands on the Hudson River were likely triggered by anthropogenic development since the onset of the industrial era, including two-thirds of the emergent cattail marsh. These inadvertently constructed tidal wetlands currently trap roughly 6% of the Hudson River's sediment load. Results indicate that when sediment is readily available, freshwater tidal wetlands can develop relatively rapidly in sheltered settings. The study sites serve as useful examples to help guide future tidal marsh creation and restoration efforts.