Journal of Environmental Monitoring最新文献

A total of 200 indoor air samples were collected to measure radon concentration levels and its contribution to the mean effective doses during different seasons of the period 2009-2010 at different sites of the five districts of Hazara division, Pakistan. The major portion of the region is mountainous and is full of thick forests which receives heavy snow fall in winter. The need for conducting the present survey relied on the fact that occupants spend their lives in poorly ventilated indoor environments of the region, especially in the winter season when they use wood fire inside their residences. The measurements of indoor air samples were taken with RAD-7, a solid state α-detector. Radon concentrations in the whole region range from 41 Bq m(-3) to 254 Bq m(-3) with a geometric mean of 128 Bq m(-3). Radon progenies were measured with a surface barrier detector through alpha spectroscopy from which the Equilibrium Factor (EF) for radon and Radon Decay Products (RDPs) for the smoke-bearing as well as smoke-free indoor environments were deduced. The respective mean values of EF were calculated as 0.49 ± 0.08 and 0.40 ± 0.07. The mean effective doses from indoor air of Abbottabad, Mansehra, Haripur, Battgram and Kohistan districts were calculated as 3.5 ± 1.2, 3.7 ± 0.7, 3.9 ± 1.0, 3.6 ± 1.1 and 3.9 ± 0.7 mSv a(-1) respectively, with the maximum value of 5.1 ± 1.8 mSv a(-1) in Kohistan district during winter and the minimum value of 2.9 ± 1.0 mSv a(-1) in Abbottabad district during summer. The annual exposure dose to the inhabitants of the locality lies below the upper bound of 10 mSv a(-1), as recommended by ICRP-65, and may not pose any significant threat to the public health.

The effect of humic acid (HA) on U(VI) sorption on bentonite was studied in batch experiments at room temperature and ambient atmosphere at a (237)U(VI) concentration of 8.4 × 10(-11) M and HA concentration of 100 mg L(-1). The distribution of U(VI) between the liquid and solid phases was studied as a function of pH and ionic strength both in the absence and presence of HA. It was shown that the uranyl sorption on bentonite is strongly dependent on pH and the presence of humics, and the effect of the addition order was negligible. In the absence of HA an enhancement in the uptake with increasing pH was observed and a sharp sorption edge was found to take place between pH 3.2 and 4.2. The presence of HA slightly increases uranium(VI) sorption at low pH and curtails it at moderate pH, compared to the absence of HA. In the basic pH range for both the presence and absence of HA the sorption of uranium is significantly reduced, which could be attributed to the formation of soluble uranyl carbonate complexes. The influence of ionic strength on U(VI) and HA uptake by bentonite were investigated in the range of 0.01-1.0 M, and while there was an enhancement in the sorption of humic acid with increasing ionic strength, no significant effect of the ionic strength on the U(VI) sorption was observed in both the absence and presence of HA.

Polycyclic aromatic hydrocarbons (PAHs) are commonly occurring environmental pollutants, 8 of which have been chosen from the list of priority substances in the EU Water Framework Directive (WFD). The levels of PAHs in the environment are affected by a number of emission factors including anthropogenic activities, population equivalents, and weather, all of which must be taken into account when monitoring levels of PAHs being released into the environment via waste water treatment plant effluent. Effluent samples have been collected from nine different wastewater treatment plants in 2 areas of Ireland (Dublin and Cork) over a period of 3 years (2009-2011), including several weeks of high intensity sampling. Solid phase extraction is used in the sample preparation process with subsequent analysis by gas chromatography with mass spectrometric detection (GCMS). All samples analysed contained the priority PAHs in this study; however levels detected do not exceed environmental quality standards (EQSs). Herein these results are related to a number of key emission factors affecting the levels of PAHs present in wastewater treatment plant effluent. This study aims to complement storm water studies and inform future targeted priority substance monitoring programmes.

Visible near-infrared (VisNIR) diffuse reflectance spectroscopy (DRS) is a rapid, non-destructive method for sensing the presence and amount of total petroleum hydrocarbon (TPH) contamination in soil. This study demonstrates the feasibility of VisNIR DRS to be used in the field to proximally sense and then map the areal extent of TPH contamination in soil. More specifically, we evaluated whether a combination of two methods, penalized spline regression and geostatistics could provide an efficient approach to assess spatial variability of soil TPH using VisNIR DRS data from soils collected from an 80 ha crude oil spill in central Louisiana, USA. Initially, a penalized spline model was calibrated to predict TPH contamination in soil by combining lab TPH values of 46 contaminated and uncontaminated soil samples and the first-derivative of VisNIR reflectance spectra of these samples. The r(2), RMSE, and bias of the calibrated penalized spline model were 0.81, 0.289 log(10) mg kg(-1), and 0.010 log(10) mg kg(-1), respectively. Subsequently, the penalized spline model was used to predict soil TPH content for 128 soil samples collected over the 80 ha study site. When assessed with a randomly chosen validation subset (n = 10) from the 128 samples, the penalized spline model performed satisfactorily (r(2) = 0.70; residual prediction deviation = 2.0). The same validation subset was used to assess point kriging interpolation after the remaining 118 predictions were used to produce an experimental semivariogram and map. The experimental semivariogram was fitted with an exponential model which revealed strong spatial dependence among soil TPH [r(2) = 0.76, nugget = 0.001 (log(10) mg kg(-1))(2), and sill 1.044 (log(10) mg kg(-1))(2)]. Kriging interpolation adequately interpolated TPH with r(2) and RMSE values of 0.88 and 0.312 log(10) mg kg(-1), respectively. Furthermore, in the kriged map, TPH distribution matched with the expected TPH variability of the study site. Since the combined use of VisNIR prediction and geostatistics was promising to identify the spatial patterns of TPH contamination in soils, future research is warranted to evaluate the approach for mapping spatial variability of petroleum contaminated soils.

To understand the influence of the urbanization process on the air quality in the urban neighbourhood area, the size distribution and seasonal variations of elemental and organic carbon in aerosols were studied at a coastal and suburban site in Xiamen City, China. A total of 87 samples were obtained during the one-year measurement campaign from June 2009 to May 2010. The results indicated that 79.3 ± 3.2% of the organic carbon (OC) and 88.3 ± 1.7% of the elemental carbon (EC) were associated with fine particles (PM(2.5)), which consist of 32.0 ± 8.3% of the total carbonaceous aerosol (TCA). The concentrations of the OC and EC in PM(2.5) were 17.8 ± 11.2 and 3.8 ± 1.9 μg m(-3), respectively, and high concentrations were usually observed when the wind direction was northeast (NE). High OC/EC ratios (average 5.1) in PM(2.5) indicated the formation of secondary organic carbon (SOC), which contributed 60.0% to the OC and 11.0% to the particulate matter. At this site, SOC had a significant negative correlation with the temperature (R(2) = 0.42), and a favorable meteorological condition for SOC formation was found in the wintertime. The OC/EC ratios increased with particle size, while the fractions of the carbonaceous aerosols to particulate matter decreased. OC, EC and SOC concentrations and OC/EC ratios followed the same seasonal pattern of winter > spring > autumn > summer, which mainly resulted from the various origins of the air masses in different seasons. This study indicates the requirement for mitigating the pollution of carbonaceous aerosol at this coastal and suburban area in Xiamen City.

A battery of biomarkers of exposure (EROD, DBF, GST and GPx) and effect (lipid peroxidation and DNA damage - strand breaks) were analyzed in gill tissues from caged and native oysters Crassostrea rhizophorae exposed to two tropical estuarine systems in SW Brazil: Santos (S1, S2, S3, S4) and Paranaguá (P1 - control, P2, P3, P4). The exposure lasted 28 days. Native oysters were sampled in the same areas where caged systems were exposed. Significant induction of biomarkers of exposure to organic compounds and oxidative stress (p < 0.05) were observed in all transplanted individuals from Santos resulting in DNA damage and lipid peroxidation. Biological adverse effects were more evident in oysters transplanted in the Santos Estuarine System, a recognized contaminated area, than in the Paranaguá Estuarine System, surrounded by urban areas and Environmental Protected Areas. Native specimens from both estuaries showed adaption to the impacts of several contamination sources affecting the ecosystem. The use of transplanted C. rhizophorae proved to be a suitable tool for assessing and monitoring the environmental quality in mangrove ecosystems. This integrated approach employing multi-biomarker responses under field conditions could be incorporated as a descriptor of health status in tropical estuarine systems.

The characteristics of nitrate (NO(3)(-)) in major rivers and aquifers of the Sanjiang Plain, China were investigated by hydrogeochemical conditions, nitrogen isotope technique and CFCs trace. An overall understanding on the sources and fate of NO(3)(-) in the surface water and the groundwater was obtained. The NO(3)(-) concentrations in the surface water were low and no samples exceeds the WTO standards. However, 11.4% of the groundwater samples exceeded the WTO standards, indicating local NO(3)(-) pollution in rural areas. Redox condition analysis revealed that most of the surface water had oxic condition, while for the shallow groundwater (mean well depth smaller than 30 m), the redox condition began to change into anoxic zone, and the deep groundwater (mean well depth larger than 50 m) showed strong anoxic condition. The δ(15)N-NO(3) data indicated soil N and fertilizer contributed the major sources in the surface water, and NO(3)(-) in the groundwater mainly showed a manure origin. In the Songhua-Heilong River, dilution effect was dominating, while for the Wusuli River, it showed that mix with water contained excess of NO(3)(-) resulted in the NO(3)(-) concentration increased along the river. Additionally, the NO(3)(-) transportation in the groundwater was analyzed by groundwater ages derived from environmental tracer (CFCs) data. The relation between the groundwater ages and the NO(3)(-) concentrations showed that the young groundwater with the age less than 60 years had higher NO(3)(-) concentrations than the old groundwater over the age of 60 years because anthropogenic activities began to boom from 1950s in the Sanjiang Plain.

A three-week-long biological sampling scheme was conducted in two child daycare centers (CDCCs) in order to investigate interdiurnal and diurnal variations in indoor airborne microbes as well as the efficiency of weak acid hypochlorous water (WAHW) on disinfecting indoor microbes. During the second week of sampling, WAHW was sprayed using a fogger in the classroom after children had left and before they returned the next morning. An identical cycle of experiments was performed twice in the winter and spring. Without WAHW intervention, the respective mean of the indoor concentrations and I/O ratios were 8732-47581 CFU m(-3) and 0.96-2.53 for fungi, and 6706-28998 CFU m(-3) and 1.10-11.92 for bacteria, showing severe bio-contamination in the CDCCs. Moreover, a relatively high level of bacterial pollution was found at noon, whereas a greater fungal pollution could be detected in the morning and at noon. Among five school days, the fungal and bacterial pollution may be higher on Monday and on Wednesday, Thursday, and Friday, respectively. Furthermore, with WAHW intervention, the indoor microbial concentrations and I/O ratios were decreased significantly. The reduction of I/O ratios caused by WAHW disinfection was accomplished in the morning for bacteria and in the morning, at noon, and in the afternoon for fungi. In conclusion, this study clearly clarified the risky period during which children may be exposed to hazardous environments, and demonstrated the effectiveness of spraying WAHW the night before on decontaminating indoor airborne microbes on the following day, especially in the case of fungi.

Ultraviolet/visible (UV/Vis) absorbance spectroscopy is a commonly used technique for characterizing dissolved organic matter (DOM). We present an analysis of UV/Vis absorbance spectra from 983 lakes throughout Sweden, sampled during autumn 2009. Metrics included both specific absorbances (i.e. absorbance per mass unit of organic carbon), and descriptions of spectral shape. Overall, we found three factors to which all spectral metrics were similarly related: acidity, retention-time, and latitude. In general, alkaline lakes with a long retention time in northern Sweden have lower specific absorbance and steeper spectral slope than acidic lakes with a short retention time in southern Sweden. Relative to the specific absorbance measured at 254 nm (SUVA), commonly used as a measure of DOM aromaticity, the specific absorbance at longer wavelengths and metrics of spectral shape were more sensitive to acidity and less sensitive to latitude. Although different spectral metrics are hypothesized to reflect different properties of DOM, UV/Vis absorbance spectroscopy may not be useful for more refined characterization of organic matter because of the strong inter-correlation between metrics. Nevertheless, it remains useful as a quick, cheap and reliable method of estimating DOM quantity and describing quality. We suggest that the most informative range to measure absorbance is between approximately 250 and 360 nm, where the between-lake variability is largest and absorbance can, in general, be precisely measured.

Greenhouse gas (GHG; methane and nitrous oxide) emissions from enteric fermentation and manure management of Indian livestock were estimated from the last two Indian livestock census datasets (2003 and 2007) using IPCC Tier 2 (2006) guidelines. The total annual GHG emissions from Indian livestock increased in 2007 compared to the year 2003 with an annual growth rate of 1.52% over this period. The contributions of GHG by dairy cattle, non-dairy cattle, buffaloes, goats, sheep and other animals (yak, mithun, horse, donkeys, pigs and poultry) were 30.52, 24.0, 37.7, 4.34, 2.09 and 3.52%, respectively, in 2007. Enteric fermentation was the major source of methane, accounting for 89.2% of the total GHG emissions, followed by manure methane (9.49%). Nitrous oxide emissions accounted for 1.34%. GHG emissions (CO(2)-eq. per kg of fat and protein corrected milk (FPCM)) by female animals were considerably lower for crossbred cows (1161 g), followed by buffaloes (1332 g) and goats (2699 g), and were the highest for indigenous cattle (3261 g) in 2007. There was a decreasing trend in GHG emissions (-1.82% annual growth rate) in relation to milk production from 2003 to 2007 (1818 g and 1689 g CO(2)-eq. per kg FPCM in 2003 and 2007, respectively). This study revealed that GHG emissions (total as well as per unit of products) from dairy and other categories of livestock populations could be reduced substantially through proper dairy herd management without compromising animal production. In conclusion, although the total GHG emissions from Indian livestock increased in 2007, there was a decreasing trend in GHG production per kg of milk production or animal products.