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881.
MW Nonnenmann G Coronado B Thompson WC Griffith JD Hanson S Vesper EM Faustman 《Journal of environmental monitoring : JEM》2012,14(8):2038-2043
Molecular techniques are an alternative to culturing and counting methods in quantifying indoor fungal contamination. Pyrosequencing offers the possibility of identifying unexpected indoor fungi. In this study, 50 house dust samples were collected from homes in the Yakima Valley, WA. Each sample was analyzed by quantitative PCR (QPCR) for 36 common fungi and by fungal tag-encoded flexible (FLX) amplicon pyrosequencing (fTEFAP) for these and additional fungi. Only 24 of the samples yielded amplified results using fTEFAP but QPCR successfully amplified all 50 samples. Over 450 fungal species were detected by fTEFAP but most were rare. Twenty-two fungi were found by fTEFAP to occur with at least an average of ≥0.5% relative occurrence. Many of these fungi seem to be associated with plants, soil or human skin. Combining fTEFAP and QPCR can enhance studies of fungal contamination in homes. 相似文献
882.
Sarath K. Guttikunda Ramani V. Kopakka Prasad Dasari Alan W. Gertler 《Environmental monitoring and assessment》2013,185(7):5585-5593
Air quality in Hyderabad, India, often exceeds the national ambient air quality standards, especially for particulate matter (PM), which, in 2010, averaged 82.2?±?24.6, 96.2?±?12.1, and 64.3?±?21.2 μg/m3 of PM10, at commercial, industrial, and residential monitoring stations, respectively, exceeding the national ambient standard of 60 μg/m3. In 2005, following an ordinance passed by the Supreme Court of India, a source apportionment study was conducted to quantify source contributions to PM pollution in Hyderabad, using the chemical mass balance (version 8.2) receptor model for 180 ambient samples collected at three stations for PM10 and PM2.5 size fractions for three seasons. The receptor modeling results indicated that the PM10 pollution is dominated by the direct vehicular exhaust and road dust (more than 60 %). PM2.5 with higher propensity to enter the human respiratory tracks, has mixed sources of vehicle exhaust, industrial coal combustion, garbage burning, and secondary PM. In order to improve the air quality in the city, these findings demonstrate the need to control emissions from all known sources and particularly focus on the low-hanging fruits like road dust and waste burning, while the technological and institutional advancements in the transport and industrial sectors are bound to enhance efficiencies. Andhra Pradesh Pollution Control Board utilized these results to prepare an air pollution control action plan for the city. 相似文献
883.
M. Arana R. San Martin I. Nagore D. Pérez 《Environmental monitoring and assessment》2013,185(6):4951-4957
According to Directive 2002/49, strategic noise maps and their correspondent action plans were carried out in the Autonomous Community of Navarre, Spain. Six strategic noise maps were produced for 120 km of major roads as well as a strategic noise map for the Agglomeration of the Region of Pamplona (ARP) with a population of 280,199 inhabitants. In the ARP, a total of 36,400 people (13.0 %) are exposed to Ln levels over 55 dBA and 42,300 people (15.1 %) are exposed to Lden levels over 65 dBA. With regard to major roads, a total of 3,900 people are exposed to Ln levels over 55 dBA and 2,400 people are exposed to Lden levels over 65 dBA. When designing action plans, different prioritisation criteria concerning rank-based effectiveness measures (mainly the amount of people benefitting from them) were taken into account. 相似文献
884.
885.
Alam R Munna G Chowdhury MA Sarkar MS Ahmed M Rahman MT Jesmin F Toimoor MA 《Environmental monitoring and assessment》2012,184(1):573-580
In rural areas in Bangladesh, groundwater is the principal source of water supply. This underground water is available in
considerable amount in shallow aquifers. It is free from pathogenic microorganisms and hence water-borne diseases. In plain
lands, other than hilly areas, water supply to 97% rural population comes from tube-wells, which is regarded to be a phenomenal
achievement in preserving public health. Besides, a dependable water supply system all throughout the country is offset by
two factors: (a) high salinity in surface plus groundwater in coastal areas; (b) want of suitable groundwater aquifers in
hilly areas and the high cost of setting up tube-wells due to deep underground water table and stony layers. However, presence
of arsenic in underground water now poses a serious threat to the success once made in water supply by setting up of manually
operated tube-wells in the village areas—the achievement is now on the brink of total collapse. In about 61 districts out
of 64, presence of arsenic exceeds a quantity of 0.05 mg/1, a permissible limit as per Bangladeshi water quality standard.
Harvesting rainwater can be a pragmatic solution to this problem, which is common in many places in Sylhet especially in the
hilly areas on the north eastern part of the city. This can be an alternative source of drinking water because of availability
of rainwater from March to October. Heavy rain occurs from end of May till mid September, which is commonly known as the rainy
season. This paper focuses on the possibility of harvesting rainwater in rural communities and thickly populated urban areas
of Sylhet. It also demonstrates the scopes of harvesting rainwater using simple and low-cost technology. With setting up of
a carefully planned rainwater storage tank, a family can have all of its drinking water from rain. Planned use of rainwater
through rainwater harvesting in the roof catchments may fulfill the entire annual domestic water demand of a family in the
rural areas of Bangladesh. 相似文献
886.
Chlorinated paraffins (CPs) are straight chain hydrocarbons that are produced as complex mixtures and are used as flame retardants
and paint additives. These mixtures are extremely difficult to characterize using conventional chromatographic methods, as
conventional gas chromatography results in unresolved complex chromatograms that preclude the identification and quantification
of individual congeners or any reasonable assessment of the average carbon chain length. Carbon chain length is an important
parameter for assessing physical properties and the toxicity of these materials. We have modified and improved a previously
published gas chromatography–flame ionization detector method that uses Pd catalyst held in the gas chromatograph injector
to simultaneously dechlorinate the CPs and separate the resulting alkanes. In addition, we have adapted this method to gas
chromatography–mass spectrometry. Dehalogenation of other compounds was also studied with this system to investigate potential
application to other complex halogenated mixtures. 相似文献
887.
Gas–particle concentration,distribution, and health risk assessment of polycyclic aromatic hydrocarbons at a traffic area of Giza,Egypt 总被引:1,自引:0,他引:1
Atmospheric particulate and gaseous polycyclic aromatic hydrocarbons (PAHs) samples were collected from an urban area in Dokki
(Giza) during the summer of 2007 and the winter of 2007–2008. The average concentrations of PAHs were 1,429.74 ng/m3 in the particulate phase, 2,912.56 ng/m3 in the gaseous phase, and 4,342.30 ng/m3 in the particulate + gaseous phases during the period of study. Dokki has high level concentrations of PAH compounds compared
with many polluted cities in the world. The concentrations of PAH compounds in the particulate and gaseous phases were higher
in the winter and lower in the summer. Total concentrations of PAHs in the particulate phase and gaseous phase were 22.58%
and 77.42% in summer and 36.97% and 63.03% in winter of the total (particulate + gaseous) concentrations of PAHs, respectively.
The gaseous/particulate ratios of PAHs concentration were 3.43 in summer and 1.71 in winter. Significant negative correlation
coefficients were found between the ambient temperature and concentrations of the total PAHs in the particulate and gaseous
phases. The distribution of individual PAHs and different categories of PAHs based on aromatic ring number in the particulate
and gaseous phases during the summer and winter were nearly similar, indicating similar emission sources of PAHs in both two
seasons. Benzo(b)fluoranthene in the particulate phase and naphthalene in the gaseous phase were the most abundant compounds. Diagnostic concentration
ratios of PAH compounds indicate that these compounds are emitted mainly from pyrogenic sources, mainly local vehicular exhaust
emissions. Health risks associated with the inhalation of individual PAHs in particulate and gaseous phases were assessed
on the basis of its benzo(a)pyrene equivalent concentration. Dibenzo(a,h)anthracene and benzo(a)pyrene in the particulate phase and benzo(a)pyrene and benzo(a)anthracene in the gaseous phase were the greatest contributors to the total health risks. The relative mean contributions
of the total carcinogenic activity (concentrations) of all PAHs to the total concentrations of PAHs were 29.37% and 25.15%
in the particulate phase and 0.76% and 0.92% in the gaseous phase during the summer and winter, respectively. These results
suggest that PAHs in the particulate phase in the ambient air of Dokki may pose a potential health risk. 相似文献
888.
Langston WJ O'Hara S Pope ND Davey M Shortridge E Imamura M Harino H Kim A Vane CH 《Environmental monitoring and assessment》2012,184(1):289-311
Biomonitoring of contaminants (metals, organotins, polyaromatic hydrocarbons (PAHs), PCBs) was undertaken in Milford Haven
Waterway (MHW) and a reference site in the Tywi Estuary (St Ishmael/Ferryside) during 2007–2008. Bioindicator species encompassed
various uptake routes—Fucus vesiculosus (dissolved contaminants); Littorina littorea (grazer); Mytilus edulis and Cerastoderma edule (suspension feeders); and Hediste (=Nereis) diversicolor (sediments). Differences in feeding and habitat preference have subtle implications for bioaccumulation trends though, with
few exceptions, contaminant burdens in MHW were higher than the Tywi reference site, reflecting inputs. Elevated metal concentrations
were observed at some MHW sites, whilst As and Se (molluscs and seaweed) were consistently at the higher end of the UK range.
However, for most metals, distributions in MH biota were not exceptional. Several metal-species combinations indicated increases
in bioavailability upstream, which may reflect the influence of geogenic/land-based sources—perhaps enhanced by lower salinity.
TBT levels in MH mussels were below OSPAR toxicity thresholds and in the Tywi were close to zero. Phenyltins were not accumulated
appreciably in M. edulis, whereas some H. diversicolor populations appear subjected to localized (historical) sources. PAHs in H. diversicolor were distributed evenly across most of MHW, although acenaphthene, fluoranthene, pyrene, benzo(a)anthracene and chrysene were highest at one site near the mouth; naphthalenes in H. diversicolor were enriched in the mid-upper Haven (a pattern seen in M. edulis for most PAHs). Whilst PAH (and PCB) concentrations in MH mussels were mostly above reference and OSPAR backgrounds, they
are unlikely to exceed ecotoxicological thresholds. Bivalve Condition indices (CI) were highest at the Tywi reference site
and at the seaward end of MH, decreasing upstream—giving rise to several significant (negative) relationships between CI and
body burdens. Despite the possible influence of salinity gradient as a complicating factor, multivariate analysis indicated
that a combination of contaminants could influence the pattern in condition (and the biomarkers metallothionein and TOSC).
Integrating bioaccumulation data with biological and biochemical endpoints is seen as a useful way to discriminate environmental
quality of moderately contaminated areas such as MHW and to prioritise cause and effect investigations. 相似文献
889.
Alexander Lorenz Matthias G. W. Schmidt Elmar Kriegler Hermann Held 《Environmental Modeling and Assessment》2012,17(1-2):163-175
Several integrated assessment studies have concluded that future learning about the uncertainties involved in climate change has a considerable effect on welfare but only a small effect on optimal short-term emissions. In other words, learning is important but anticipation of learning is not. We confirm this result in the integrated assessment model “model of investment and technological development” for learning about climate sensitivity and climate damages. If learning about an irreversible threshold is included, though, we show that anticipation can become crucial both in terms of necessary adjustments of pre-learning emissions and resulting welfare gains. We specify conditions on the time of learning and the threshold characteristic, for which this is the case. They can be summarized as a narrow “anticipation window.” 相似文献
890.
Agunbiade FO Olu-Owolabi BI Adebowale KO 《Environmental monitoring and assessment》2012,184(1):89-102
The accumulation patterns of ten metals in tissues of plant, Eichornia crassipes, and fishes, Hydrocynus forskahlii and Oreochromis mossambicus, were modeled with simple fuzzy classification (SFC) to assess toxic effects of anthropogenic activities on the coastal biota.
The plant sample was separated into root, stem, and leaves and the fishes into bones, internal tissues, and muscles. They
were analyzed for As, Cd, Cr, Cu, Ni, Pb, V, Fe, Mn, and Zn after wet oxidation of their dried samples. The results were converted
into membership functions of five accumulation classes and aggregated with SFC. The classification results showed that there
was no metal accumulation in the plant parts while the fishes were classified into low accumulation category. The internal
tissues of the fishes had higher metal accumulation than the other parts. Generally, Fe and Mn had highest concentrations
in the biota but are natural to the area and may not constitute significant risk. Cr had the highest transfer and accumulation
from the coastal water into the aquatic lives and may be indicative of risk prone system being a toxic metal. Metal contaminations
in the zone had not significantly accumulated in the biota making them less prone to risk associated with metal accumulation. 相似文献