The aim of the current study was to measure polycyclic aromatic hydrocarbons (PAHs) in eight indoor (In both kitchen and living room) air sampling locations using a passive sampling method for collection. Passive outdoor air samples were also collected from 3 of the same sampling locations as the indoor air sampling sites. Sampling was conducted in three seasons. The summer season, when windows are generally open, was between 18th July and 01st September, 2014; the autumn and winter seasons, when windows are mostly closed, was between 18th October and 01st December, 2014, and 01st December, 2014, and 18th January, 2015, respectively.
Average PAH concentrations in summer were 22 ± 21 ng/m3 and 17 ± 12 ng/m3 in the living room and kitchen, respectively, whereas living room and kitchen average PAH concentrations were 23 ± 16 ng/m3 and 20 ± 9 ng/m3, respectively, in autumn and 23 ± 13 ng/m3 and 23 ± 24 ng/m3, respectively, in winter. Outdoor air PAH concentrations in summer, autumn and winter were 7 ± 0.4 ng/m3, 22 ± 13 ng/m3 and 209 ± 33 ng/m3, respectively. An increase in outdoor PAH concentrations was measured in winter compared to the concentrations in summer and autumn, which paralleled the lower outdoor air temperature. However, PAH concentrations in the indoor environment vary according to the household characteristics and personal habits. 相似文献
• Sampling parameters with high efficiency was determined.• Operational process to detect airborne ARGs was optimized.• Providing research basis to control airborne ARGs of a laboratory atmosphere Antibiotic resistance genes (ARGs) have been detected in various atmospheric environments. Airborne ARGs transmission presents the public health threat. However, it is very difficult to quantify airborne ARGs because of the limited availability of collectable airborne particulate matter and the low biological content of samples. In this study, an optimized protocol for collecting and detecting airborne ARGs was presented. Experimental results showed that recovery efficiency tended to increase initially and then declined over time, and a range of 550–780 copies/mm2 of capture loading was recommended to ensure that the recovery efficiency is greater than 75%. As the cell walls were mechanically disrupted and nucleic acids were released, the buffer wash protects ARGs dissolution. Three ratios of buffer volume to membrane area in buffer wash were compared. The highest concentrations of airborne ARGs were detected with 1.4 µL/mm2 buffer wash. Furthermore, the majority of the cells were disrupted by an ultrasonication pretreatment (5 min), allowing the efficiency ARGs detection of airborne samples. While, extending the ultrasonication can disrupt cell structures and gene sequence was broken down into fragments. Therefore, this study could provide a theoretical basis for the efficient filter collection of airborne ARGs in different environments. An optimized sampling method was proposed that the buffer wash was 1.4 µL/mm2 and the ultrasonication duration was 5 min. The indoor airborne ARGs were examined in accordance with the improved protocol in two laboratories. The result demonstrated that airborne ARGs in an indoor laboratory atmosphere could pose the considerable health risk to inhabitants and we should pay attention to some complicated indoor air environment. 相似文献
An economic and quick methodology for performing a preliminary spatial assessment of a city air quality with the purpose to
identify locations and zones susceptible to high pollution levels is proposed. A Patras case-study is selected, regarding
the air pollutants of sulfur dioxide (SO2) and oxides of nitrogen (NOx). A total number of 451 samples of short duration, of which 225 were randomly picked in morning rush hours and 226 within
evening rush hours, were collected from 50 locations of the major Patras area during a year period, when peaks of primary
air pollutants usually occur. Concentration measurements at prescribed locations used to statistically calculate spatial average
concentrations approximating 1-h mean values with mean probable errors less than 25.9% for SO2, NO and NOx and less than 15.5% for NO2. Then iso-concentration contour diagrams plotted indicate high pollution zones and possibly appropriate locations for continuous
or random monitoring according to the European Community (EC) Directives. The 1-h mean concentrations were in good correlation
to the corresponding traffic rates and useful relationships are given (0.54 ≤ r ≤ 0.63). In addition, comparisons with data available for other cities, as well as with the limit and guide values provided
by the EC and the World Health Organization (WHO) were given. The present data could be useful for the design and optimization
of a city network of stations for monitoring air quality, for environmental impact assessments, future reference and comparisons
due to city development needs, as well as for validating dispersion models. 相似文献
We explored temporal trends of young-of-year (YOY) fishes caught in bottom trawl hauls at an established offshore monitoring
site in Lake Erie in fall during 1961–2001. Sampling was conducted during morning, afternoon, and night in each year. Catches
per hour (CPH) of alewife (Alosa pseudoharengus) YOY were relatively low and exhibited no temporal trend. This result was consistent with the species’ intolerance to Lake
Erie’s adverse winter water temperatures. Gizzard shad (Dorosoma cepedianum) YOY decreased sharply after 1991, which was consistent with recent oligotrophication of the lake. Following the establishment
in 1979 and rapid increase of white perch (Morone americana) YOY, white bass (Morone chrysops) and freshwater drum (Aplodinotus grunniens) YOY decreased. Trout-perch (Percopsis omiscomaycus) YOY decreased during 1986–1991, but recovered to previous levels during 1991–2001. The recovery coincided with the resurgence
of mayflies (Ephemoptera) in the lake. CPH of spottail shiner (Notropis hudsonius) and emerald shiner (N. atherinoides) YOY exhibited no temporal trend between 1961 and the late 1970s to early 1980s. CPH of yellow perch (Perca flavescens) YOY decreased during 1961–1988, and walleye (Sander vitreum) YOY increased overall during the time series. These observations were consistent with published studies of adults in the
region. CPH of 4 of the 10 species of YOY considered were greatest during night. CPH for walleye YOY was higher in the morning
than in the afternoon, but there was no significant difference between night and morning abundances. The results suggest that
(1) CPH of YOY fishes may be a useful monitoring tool for Lake Erie, and (2) offshore monitoring programs that do not include
night sampling periods may underestimate recruitment for several common species. 相似文献
Quaternary Ammonium Compounds (QACs) are widely found in disinfectants used in hospitals. Benzalkonium chloride (BAC) and didecyldimethylammonium chloride (DDAC) predominate in the disinfecting formulations. These compounds are strong irritants and can play a role in the induction of Occupational Asthma among the professionals of health and cleaning. In order to evaluate the potential health effect of these quaternary ammonium compounds to hospital employers, the development of an analytical method for their quantification in indoor air was developed. DDAC aerosols are trapped by adsorption on XAD-2 resin SKC tube. The air in hospital buildings was sampled using a constant debit Gillian pump at a flow of 1.0 l/min (+/-5%). Ion Chromatography (IC) was chosen for the analysis of DDAC especially for its high sensitivity and specificity. The Limit of Detection (LOD) by IC for DDAC is 0.56 mug/ml. Therefore the LOD of atmospheric DDAC is 28 microg/m(3) with an air volume of 100 l and a desorption volume of 5 ml. All DDAC air samples were lower than the LOD of the analytical method by IC. Under the standard conditions of use of the disinfecting solutions (Surfanios, Ampholysine Plus and Amphospray 41), the insignificant volatility of DDAC would not seem to be able to contaminate the indoor hospital atmosphere during the disinfection process. However, the DDAC can contaminate working atmospheres if it is put in suspension by aerosolisation. 相似文献