Dynamic Exposure of Organisms and Passive Samplers to Hydrophobic Chemicals

2009 ◽  
Vol 43 (7) ◽  
pp. 2206-2215 ◽  
Author(s):  
Stéphane Bayen ◽  
Thomas L. ter Laak ◽  
Jacques Buffle ◽  
Joop L. M. Hermens
Keyword(s):  
Passive Samplers ◽  
Dynamic Exposure

scholarly journals Assessment of the Dynamic Exposure to PM2.5 Based on Hourly Cell Phone Location and Land Use Regression Model in Beijing

2021 ◽  
Vol 18 (11) ◽  
pp. 5884
Author(s):  
Junli Liu ◽  
Panli Cai ◽  
Jin Dong ◽  
Junshun Wang ◽  
Runkui Li ◽  
...  
Keyword(s):  
Land Use ◽  
Exposure Assessment ◽  
Activity Pattern ◽  
Cell Phone ◽  
Total Population ◽  
Cell Phones ◽  
Land Use Regression ◽  
Pm2.5 Exposure ◽  
Dynamic Exposure ◽  
Pm2.5 Concentration

The spatiotemporal locations of large populations are difficult to clearly characterize using traditional exposure assessment, mainly due to their complicated daily intraurban activities. This study aimed to extract hourly locations for the total population of Beijing based on cell phone data and assess their dynamic exposure to ambient PM2.5. The locations of residents were located by the cellular base stations that were keeping in contact with their cell phones. The diurnal activity pattern of the total population was investigated through the dynamic spatial distribution of all of the cell phones. The outdoor PM2.5 concentration was predicted in detail using a land use regression (LUR) model. The hourly PM2.5 map was overlapped with the hourly distribution of people for dynamic PM2.5 exposure estimation. For the mobile-derived total population, the mean level of PM2.5 exposure was 89.5 μg/m3 during the period from 2013 to 2015, which was higher than that reported for the census population (87.9 μg/m3). The hourly activity pattern showed that more than 10% of the total population commuted into the center of Beijing (e.g., the 5th ring road) during the daytime. On average, the PM2.5 concentration at workplaces was generally higher than in residential areas. The dynamic PM2.5 exposure pattern also varied with seasons. This study exhibited the strengths of mobile location in deriving the daily spatiotemporal activity patterns of the population in a megacity. This technology would refine future exposure assessment, including either small group cohort studies or city-level large population assessments.

scholarly journals Depth–Sequential Investigation of Major Ions, δ18o, δ2h and δ13C in Fractured Aquifers of the St. Lawrence Lowlands (Quebec, Canada) Using Passive Samplers

Water ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 1806
Author(s):  
Guillaume Meyzonnat ◽  
Florent Barbecot ◽  
José Corcho Alvarado ◽  
Daniele Luigi Pinti ◽  
Jean-Marc Lauzon ◽  
...  
Keyword(s):  
Stable Isotopes ◽  
Major Ions ◽  
Anthropogenic Activities ◽  
Carbon Sources ◽  
Passive Samplers ◽  
Flow Paths ◽  
Aquifer Heterogeneity ◽  
Fractured Aquifers ◽  
Fractured Carbonate ◽  
Observation Wells

General and isotopic geochemistry of groundwater is an essential tool to decipher hydrogeological contexts and flow paths. Different hydrogeochemical patterns may result from the inherent physical aquifer heterogeneity, which may go unnoticed without detailed investigations gathered from multilevel or multiple observation wells. An alternative to overcome the frequent unavailability of multiple wellbores at sites is to perform a detailed investigation on the single wellbore available. In this perspective, the aim of this study is to use passive samplers to sequentially collect groundwater at depths in long–screened wellbores. Such investigation is carried out for major ions and stable isotopes compositions (δ2H, δ18O, δ13C) at ten sites in the context of fractured carbonate aquifers of the St. Lawrence Lowlands (Quebec, Canada). The information gathered from the calco–carbonic system, major ions and stable isotopes report poorly stratified and evolved groundwater bodies. Contribution of water impacted by anthropogenic activities, such as road salts pollution and carbon sources from C4 vegetation, when they occur, are even observed at the greatest depths. Such observations suggest quick flow paths and efficient mixing conditions, which leads to significant contributions of contemporary groundwater bodies in the fractured aquifers investigated down to depths of about 100 m. Although physical aquifer investigation reported few and heterogeneously distributed fractures per wellbore, hydrogeochemical findings point to at overall well interconnected fracture networks in the aquifer and high vulnerability of groundwater, even at significant depths.

scholarly journals Long-term effects of thin layer capping in the Grenland fjords, Norway: Reduced uptake of dioxins in passive samplers and sediment-dwelling organisms

Chemosphere ◽  
2021 ◽  
Vol 264 ◽  
pp. 128544
Author(s):  
Morten Thorne Schaanning ◽  
Bjørnar Beylich ◽  
Jonas S. Gunnarsson ◽  
Espen Eek
Keyword(s):  
Thin Layer ◽  
Passive Samplers ◽  
Long Term Effects
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