Airborne Particulate Samples Research Articles

Koalas, friends and foes—The application of airborne eDNA for the biomonitoring of threatened species

Abstract Curbing global wildlife population declines will necessitate the protection of their habitat, and subsequent robust baseline information about wildlife that use and occupy it. Collating such information, however, remains a challenging and costly endeavour. Little did we know that traces of wildlife presence float in the air and can be detected through traces of DNA. Here, we deployed samplers to test the applicability of collecting airborne eDNA for the detection of a threatened species, the koala, and its co‐occurring terrestrial mammalian community. We develop a novel species specific qPCR assay to detect the presence of koalas and applied this in concert with a meta‐barcoding approach to detect the co‐occurring mammalian community. Through sampling of airborne particles, we successfully detected koala presence accurately to habitat patch level, alongside 16 unique taxonomic assignments, successfully assigning 11 of these to species level including detections belonging to the wallaby, antechinus, members of possum family and invasive species such as foxes, domestic dogs and hares. Synthesis and applications: We demonstrate the potential of airborne eDNA for the detection of threatened terrestrial wildlife and their surrounding ecological community under natural conditions. With achievable optimisations we detail how airborne eDNA may be applied for the management and monitoring of threated species for enhanced conservation efforts.

Design and performance of a novel miniaturized electrostatic sampler for efficient airborne particulate matter sampling

Design and performance of a novel miniaturized electrostatic sampler for efficient airborne particulate matter sampling

A Study of Elemental Composition and Risk Assessment Due to Exposure to Indoor PM10 in Two Residences in Mexico City

Samples of airborne particles with aerodynamic diameters smaller than 10 µm (PM10) were collected in 2021 at two households in the Metropolitan Area of Mexico City. Both sites are in areas with different characteristics (residential or industrial zones). Simultaneous sampling indoors and outdoors was carried out at the two locations, using low-volume samplers. The study aimed to determine the indoor and outdoor gravimetric mass and elemental concentrations, identify emitting sources and possible penetration towards the households enhanced by natural ventilation, and assess risks to human health due to inhalation, ingestion, and dermal absorption, through hazard quotients. Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Br, Se, and Pb concentrations were measured with X-ray fluorescence. Mass concentrations were higher indoors than outdoors, and most elemental concentrations had similar values in both environments. Cluster analysis was applied to identify possible emitting sources. The results showed a strong penetration of geogenic and industrial emissions at the Iztapalapa site, while only particles of industrial origin entered the interior of the Tlalnepantla dwelling, in both cases caused by the natural ventilation of the households. Health risks due to exposure to particles containing Fe, Ni, Cu, Zn, and Mn are not significant, and Pb and Cr only pose a risk via ingestion for men and women, although for children, there is a risk due to ingestion of all these elements.

Development of analytical methods for the determination of 3-hydroxy fatty acids and muramic acid as bacterial markers in airborne particles and settled dust

Inhalation of airborne bacteria in indoor environments is known to be associated with respiratory diseases. Analytical methods for the determination of 3-hydroxy fatty acids (3-OHFAs) and muramic acid (MA) as chemical markers of gram-negative and gram-positive bacteria, respectively, were developed for airborne particle and dust samples in this study. 3-OHFAs as markers of endotoxin were released and esterified during the hydrolysis process under methanolic acid conditions, and their hydrolysates, i.e., 3-OHFA methyl esters, were cleaned up by solid-phase extraction using silica sorbent that provided more effective separation from interferents than polymeric sorbent through elution pattern. The SPE eluent was analyzed by GC-MS/MS measurement after the trimethylsilylation reaction. The recovery of the method ranged from 82.1 % to 103.2 %, with a limit of detection ranging from 0.5 to 1.1 ng/filter and good linearity (R2 > 0.991). For the analysis of MA, muramic acid methyl ester (MAME), a product formed during methanolic hydrolysis, was selected as a specific marker of peptidoglycan. It was the first proposed compound identified and confirmed with MS and MS/MS spectra using high-resolution measurement. In particular, the measurement of MAME providing 12.5 times greater sensitivity than MA with the application of the LC-MS/MS method is one of the notable findings of this study. The recovery by simple liquid extraction was 99.4 % following the removal of the hydrophobic matrix and neutralization with solvent reconstruction. The method displayed a LOD of 0.7 ng/filter and linearity (R2) of 0.997 through a simple pretreatment process. Both developed methods were applied and evaluated by determining 3-OHFAs and MA in airborne particles collected from multipurpose facilities and settled dust in the laboratory and office.

Study of the naturally occurring radionuclide Beryllium-7 (Be-7) in Hong Kong

Beryllium-7 (Be-7) is one of the naturally occurring radionuclides being monitored under the Global Atmosphere Watch Programme of the World Meteorological Organization. Be-7 mainly originates from cosmic rays. It can be used as a tracer to facilitate understanding of the atmospheric vertical transport by observing its spatial and temporal distribution characteristics.The Hong Kong Observatory has been operating an environmental radiation monitoring programme for decades, and long record of Be-7 activity concentration data in airborne particulate samples are available to characterize the behaviour of Be-7 in the lower atmosphere in Hong Kong.In this study, Be-7 activity concentration data of airborne particulates collected at three locations in Hong Kong from 1993 to 2020 are examined. Temporal variations are analyzed. In particular, the long-term monthly average Be-7 activity concentrations are found to be most sensitive to precipitation. The relevant data analysis, as well as key factors affecting the Be-7 activity concentrations in the lower atmosphere in Hong Kong, will be described.

Physicochemical Characteristics and Occupational Exposure of Silica Particles as Byproducts in a Semiconductor Sub Fab.

This study aimed to elucidate the physicochemical characteristics and occupational exposure of silica powder and airborne particles as byproducts generated from the first scrubbers of chemical vapor deposition and diffusion processes during maintenance in a semiconductor facility sub fab to reduce unknown risk factors. The chemical composition, size, morphology, and crystal structure of powder and airborne particles as byproducts were investigated using a scanning electron microscopy and transmission electron microscopy equipped with an energy dispersive X-ray spectroscopy, and an X-ray diffraction. The number and mass concentration measurements of airborne particles were performed by using an optical particle sizer of a direct-reading aerosol monitor. All powder and airborne particle samples were mainly composed of oxygen (O) and silicon (Si), which means silica. The byproduct particles were spherical and/or nearly spherical and the particle size ranged from 10 to 90 nm, based on primary particles. Most of the particles were usually agglomerated within a particle size range from approximately 100 nm to 35 µm. In addition, most of the powder samples exhibited diffraction patterns with a broad and relatively low intensity at 2θ degrees 21.6–26.7°, which is similar to that of pure amorphous silica. The above results show the byproduct particles are amorphous silica, which are considered a less toxic foam compared to crystalline silica. The number and mass concentrations of PM10 (particles less than 10 µm in diameter) ranged from 4.250–78.466 particles/cm3 and 0.939–735.531 µg/m3, respectively. In addition, 0.3–1.0 and 2.5–10 µm particles occupied the highest portion of the number and mass concentrations, respectively. Meanwhile, several peak exposure patterns were observed at a specific step, which is the process of removing powder particles on the inner chamber and cleaning the chamber by using a vacuum cleaner and a clean wiper, during the maintenance task.

Measurement of size-segregated airborne particulate bound polycyclic aromatic compounds and assessment of their human health impacts - A case study in a megacity of southwest China

Particle size distribution of particulate polycyclic aromatic compounds (PACs) is one of the important factors controlling human exposure to PACs in air. In this study, size-segregated airborne particle samples were collected in a megacity in southwest China to analyze PACs concentrations and evaluate related health risks. Annual average concentrations of Σ19PAHs (polycyclic aromatic hydrocarbons, 17.4 ng/m3) and Σ10OPAHs (oxygenated PAHs, 15.3 ng/m3) were one order of magnitude higher than those of Σ9MPAHs (methyl PAHs, 0.97 ng/m3) and Σ27NPAHs (nitrated PAHs, 1.54 ng/m3). More than 55% of PACs masses were associated with fine particles (aerodynamic diameter Dae < 2.1 μm). Inhalation exposure assessment showed that less than 60% of particulate bound PACs could deposit in the respiratory tract, which implies that the traditional model using ambient concentration of PACs would overestimate the inhalation risk. On the other hand, incremental lifetime cancer risks from dermal absorption (ILCRderm) were comparable to those from inhalation (ILCRinh) exposure despite the much lower daily dermal absorption dose than the daily inhalation dose, which implies that the health impact might be underestimated if only considering inhalation exposure. Cancer risks from inhalation exposure were mainly attributed to fine particles while those from dermal exposure were mostly associated with coarse particles. Although neither ILCRderm nor ILCRinh exceeded the threshold value of 10−6 set by USEPA, the total ILCR exceeded this criterion, manifesting potential health risks from exposure to airborne particulate PACs in this region.

A Year-Round Measurement of Water-Soluble Trace and Rare Earth Elements in Arctic Aerosol: Possible Inorganic Tracers of Specific Events

This study presents the year-round variability of the water-soluble fraction of trace elements (wsTE) and rare earth elements (wsREE) among size segregated airborne particulate matter samples collected at Ny-Ålesund in the Svalbard Archipelago from 26 February 2018 to 26 February 2019. Six different aerosol dimensional fractions were collected using a multi-stage Andersen impactor to better understand local and global circulation with the aim of disentangling the source of inorganic tracers from specific natural or anthropogenic sources. The wsTE and wsREE content, especially in the finest fractions in remote areas, is primarily related to long-range transport and it gives valuable information on (1) the global circulation, (2) the natural sources and (3) the contribution of human activities to aerosol composition. A Factor Analysis was applied to the dataset, including levoglucosan and methanesulfonic acid (MSA), to assess the possibility of using certain inorganic tracers as indicators of specific transport events or circulation regimes. We also investigate back-trajectories to determine potential source areas.

Polycyclic aromatic hydrocarbons in airborne particulate matter samples from Hanoi, Vietnam: Particle size distribution, aryl hydrocarbon ligand receptor activity, and implication for cancer risk assessment

Concentrations and profiles of unsubstituted and methylated polycyclic aromatic hydrocarbons (PAHs and Me-PAHs) were analyzed in airborne particulate matter (PM) samples collected from high-traffic roads in Hanoi urban area. Levels of PAHs and Me-PAHs ranged from 210 to 660 (average 420) ng/m3 in total PM, and these pollutants were mainly associated with fine particles (PM2.5) rather than coarser ones (PM > 10 and PM10). Proportions of high-molecular-weight compounds (i.e., 5- and 6-ring) increased with decreasing particle size. Benzo[b+k]fluoranthene, indeno[1,2,3-cd]pyrene, and benzo[ghi]perylene were the most predominant compounds in the PM2.5 samples. In all the samples, Me-PAHs were less abundant than unsubstituted PAHs. The PAH-CALUX assays were applied to evaluate aryl hydrocarbon receptor (AhR) ligand activities in crude extracts and different fractions from the PM samples. Benzo[a]pyrene equivalents (BaP-EQs) derived by the PAH-CALUX assays for low polar fractions (mainly PAHs and Me-PAHs) ranged from 300 to 840 ng/m3, which were more consistent with theoretical values derived by using PAH-CALUX relative potencies (270–710 ng/m3) rather than conventional toxic equivalency factor-based values (22–69 ng/m3). Concentrations of PAHs and Me-PAHs highly correlated with bioassay-derived BaP-EQs. AhR-mediated activities of more polar compounds and interaction effects between PAH-related compounds were observed. By using PAH-CALUX BaP-EQs, the ILCR values ranged from 1.0 × 10−4 to 2.8 × 10−4 for adults and from 6.4 × 10−5 to 1.8 × 10−4 for children. Underestimation of cancer risk can be eliminated by using effect-directed method (e.g., PAH-CALUX) rather than chemical-specific approach.

Measurements of Natural Radionuclides and 137Cs in Airborne Particulate Samples Collected from Bali and Lombok Islands (Indonesia)

Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman","serif";} Bali and Lombok islands are popular resorts and tourist destinations in the world because of their culture and beautiful natural view. The natural and anthropogenic radionuclides content in surface air of Bali and Lombok islands such as 226 Ra, 232 Th, 40 K and 137 Cs were measured at 3 monitoring stations in a period from January to December 2016. Aerosol samples were collected using a high volume total suspended particles (TSP) sampler. The activity concentrations of those radionuclides in airborne particulate matter were measured using gamma-ray spectrometry. The results show that the activity concentrations of natural radionuclides 226 Ra, 232 Th, and 40 K ranged from 1.0 to 3.04 µBq/m 3 , not detected to 1.78 µBq/m 3 , and 0.03 to 0.49 mBq/m 3 , respectively. All airborne particulate matter filter samples were found to be lower than the minimum detectable activity for 137 Cs, which means that none of 137 Cs is originated from atmospheric nuclear weapon test and other sources in surface air of Bali and Lombok islands. Variations of monthly activity concentrations of natural radionuclides were influenced by rainfall during study period. Furthermore, the peak concentrations of radionuclides also occur due to volcanic ash coming from Mount Rinjani eruption.

A field study on the possible attachment of DPM and respirable dust in mining environments

Typcial monitoring procedures for diesel particulate matter (DPM) in mines include the collection of filter samples using particle size selectors. The size selectors are meant to separate the DPM, which is generally considered to occur in the submicron range (i.e., < 0.8 μm), from larger dust particles that could present analytical interferences. However, previous studies have demonstrated that this approach can sometimes result in undersampling, therefore, excluding significant fractions of the DPM mass. The excluded fraction may represent oversized DPM particles, but another possibility is that submicron DPM attaches to supramicron dust particles such that it is effectively oversized. To gain insights into this possibility, a field study was conducted in an underground stone mine. Submicron, respirable, and total airborne particulate filter samples were collected in three locations to determine elemental carbon (EC) and total carbon (TC), which are commonly used as analytical surrogates for DPM. Concurrent with the collection of the filter samples, a low-flow sampler with an electrostatic precipitator was also used to collect airborne particulates onto 400-mesh copper grids for analysis by transmission electron microscope (TEM). Results indicated that, while typical submicron sampling did account for the majority of DPM mass in the study mine, DPM-dust attachment can indeed occur. The effect of exposure to such attached particulates has not been widely investigated.

Characterization of airborne particulate fractions from the port city of Rijeka, Croatia

The aim of this work was characterization of airborne particulates in the port city of Rijeka in order to evaluate impact of ship emissions on air quality. Samples of airborne particulates were collected with a ten stages cascade impactor during two campaigns: autumn and spring. A total of 16 weekly samples were analyzed on mass concentration, ions, metals and carbonaceous species (EC, OC, WSOC). Distribution of airborne fractions showed a bimodal distribution, with two maxima: one in coarse, and other in fine fraction. Source apportionment using PMF receptor model identified six sources of airborne particulates in Rijeka: crustal, biomass burning, sea salt, traffic/metal industry, combustion/SIA and HFO burning, i.e., ship emission (contribution 3%). The contribution of ship traffic to primary emission of particulate matter, using vanadium as tracer, indicated a twofold increase for PM10 and PM2.5 relative to 2012–14. An unusual desert dust event was registered in autumn campaign.

Sample preparation and instrumental methods for illicit drugs in environmental and biological samples: A review

Detection of illicit drugs in the environmental samples has been challenged as the consumption increases globally. Current review examines the recent developments and applications of sample preparation techniques for illicit drugs in solid, liquid, and gas samples. For solid samples, traditional sample preparation methods such as liquid-phase extraction, solid-phase extraction, and the ones with external energy including microwave-assisted, ultrasonic-assisted, and pressurized liquid extraction were commonly used. The sample preparation methods mainly applied for liquid samples were microextraction techniques including solid-phase microextraction, microextraction by packed sorbent, dispersive solid-phase extraction, dispersive liquid-liquid microextraction, hollow fiber-based liquid-phase microextraction, and so on. Capillary microextraction of volatiles and airborne particulate sampling were primarily utilized to extract illicit drugs from gas samples. Besides, the paper introduced recently developed instrumental techniques applied to detect illicit drugs. Liquid chromatograph mass spectrometry and gas chromatograph mass spectrometry were the most widely used methods for illicit drugs samples. In addition, the development of ambient mass spectrometry techniques, such as desorption electrospray ionization mass spectrometry and paper spray mass spectrometry, created potential for rapid in-situ analysis.

Occupational exposure of health care personnel to SARS-CoV-2 particles in the intensive care unit of Tehran hospital

The outbreak of SARS-CoV-2 (COVID-19) has attracted much attention to study its possible presence and airborne transmission. The possibility of COVID-19 airborne transmission in indoor environments is debatable. The present study examined the concentration of viral RNA-containing particles produced directly or indirectly by breathing or coughing of confirmed COVID-19 patients or by carriers without symptoms. Some studies do not accept this method of transmission (COVID-19 airborne transmission). The present study aimed to measure the possible exposure of health care personnel to SARS-CoV-2 particles that may have been suspended in the air to respond to the hypothesis of COVID-19 airborne transmission. Airborne particle sampling was performed using impingement method based on NIOSH (chapter BA) and ASHRAE. Selection of sampling sections was in line with the WHO guidelines. The samples were analyzed using RT-PCR technique. Based on the given results, airborne particles of COVID-19 may present in the air and affect the health of hospital personnel. In fact, the analysis of gene expression in ambient conditions and thereby aerosol transmission of SARS-CoV-2 through air is possible and may lead to occupational exposure of health care personnel. Furthermore, it was found that airborne emission of COVID-19 through the breathing zone of patients, particularly in ICU wards with confirmed cases of COVID-19, may be higher than in other ICU wards. Also, the demonstrated results showed that there is a possibility of reaerosolization (reintroduction) of previously airborne SARS-CoV-2 particles into the atmosphere due to health care personnel frequently walking between different wards and stations of ICU.

Decoding personal biotic and abiotic airborne exposome.

The complexity and dynamics of human diseases are driven by the interactions between internal molecular activities and external environmental exposures. Although advances in omics technology have dramatically broadened the understanding of internal molecular and cellular mechanisms, understanding of the external environmental exposures, especially at the personal level, is still rudimentary in comparison. This is largely owing to our limited ability to efficiently collect the personal environmental exposome (PEE) and extract the nucleic acids and chemicals from PEE. Here we describe a protocol that integrates hardware and experimental pipelines to collect and decode biotic and abiotic external exposome at the individual level. The described protocol has several advantages over conventional approaches, such as exposome monitoring at the personal level, decontamination steps to increase sensitivity and simultaneous capture and high-throughput profiling of biotic and abiotic exposures. The protocol takes ~18 h of bench time over 2-3 d to prepare samples for high-throughput profiling and up to a couple of weeks of instrumental time to analyze, depending on the number of samples. Hundreds to thousands of species and organic compounds could be detected in the airborne particulate samples using this protocol. The composition and complexity of the biotic and abiotic substances are heavily influenced by the sampling spatiotemporal factors. Basic skillsets in molecular biology and analytical chemistry are required to carry out this protocol. This protocol could be modified to decode biotic and abiotic substances in other types of low or ultra-low input samples.

Presence of SARS-CoV-2 in the air of public places and transportation

This study investigated the presence of SARS-CoV-2 in air of public places such as shopping centers, a post office, banks, governmental offices, and public transportation facilities including an airport, subways, and buses in Tehran, Iran. A total of 28 air samples were collected from the eight groups of public and transportation locations. The airborne particle samples were collected on PTFE or glass fiber filters using two types of samplers with flow rates of 40 and 3.5 L/min, respectively. The viral samples were leached and concentrated, and RNA was extracted from each. The presence of viral RNA was evaluated using novel coronavirus nucleic acid diagnostic real time PCR kits. In 64% of the samples, SARS-CoV-2 RNA (62% and 67% from the public places and transportation, respectively) was detected. Positive samples were detected in banks (33%), shopping centers (100%), governmental offices (50%), the airport (80%), subway stations (50%), subway trains (100%), and buses (50%). Logistic regression showed that number of people present during the sampling and the sampled air volume were positively associated with presence of SARS-CoV-2; while the percentage of people with masks, air temperature, and sampling site's volume were negatively related to SARS-CoV-2's presence. However, none of these associations were statistically significant. This study showed that most public places and transportation vehicles were contaminated with SARS-CoV-2. Thus, strategies to control the spread of COVID-19 should include reducing the number of people in indoor spaces, more intense disinfection of transport vehicles, and requiring people to wear masks.

Evaluation of uncertainties measurement in EDXRF for air filter analysis

Energy Dispersive X-Ray Fluorescence (EDXRF) is one of the nuclear analytical techniques that has been widely used for elemental analysis, especially for air filter analysis. EDXRF Epsilon 5 has been installed in BATAN Bandung laboratory, Indonesia. EDXRF Epsilon 5 is an analytical instrument that is used to determine trace elements in many kinds of materials, especially in air filter samples. Measurement conditions have to be set up to determine several elements. Uncertainty evaluation was different according to the instrument used in each laboratory. This activity is aimed to calculate and evaluate the uncertainty measurement associated with EDXRF Epsilon 5 for air filter analysis. Evaluation of uncertainties measurement in EDXRF Epsilon 5 was carried out following the guides to express uncertainty: JCGM 100:2008 and EURACHEM. The uncertainty evaluation focused on 10 elements: Na, Si, S, K, Ca, Ti, Fe, Zn, Br, and Pb that generally existed in airborne particulate samples. The uncertainties results for 10 selected elements measured with Epsilon 5 were in a good correlation, with % relative uncertainty were ranged from 2% to 32%.

Aquatic toxicity of particulate matter emitted by five electroplating processes in two marine microalgae species.

Electroplating is a widely used group of industrial processes that make a metal coating on a solid substrate. Our previous research studied the concentrations, characteristics, and chemical composition of nano- and microparticles emitted during different electroplating processes. The objective of this study was to evaluate the environmental toxicity of particulate matter obtained from five different electrochemical processes. We collected airborne particle samples formed during aluminum cleaning, aluminum etching, chemical degreasing, nonferrous metals etching, and nickel plating. The toxicity of the particles was evaluated by the standard microalgae growth rate inhibition test. Additionally, we evaluated membrane potential and cell size changes in the microalgae H. akashiwo and P. purpureum exposed to the obtained suspensions of electroplating particles. The findings of this research demonstrate that the aquatic toxicity of electroplating emissions significantly varies between different industrial processes and mostly depends on particle chemical composition and solubility rather than the number of insoluble particles. The sample from an aluminum cleaning workshop was significantly more toxic for both microalgae species compared to the other samples and demonstrated dose and time-dependent toxicity. The samples obtained during chemical degreasing and nonferrous metals etching processes induced depolarization of microalgal cell membranes, demonstrated the potential of chronic toxicity, and stimulated the growth rate of microalgae after 72 h of exposure. Moreover, the sample from a nonferrous metals etching workshop revealed hormetic dose-response toxicity in H. akashiwo, which can lead to harmful algal blooms in the environment.

Plasticizer contamination in the urine and hair of preschool children, airborne particles in kindergartens, and drinking water in Hong Kong.

Common plasticizers and their alternatives are environmentally ubiquitous and have become a global problem. In this study, common plasticizers (phthalates and metabolites) and new alternatives [bisphenol analogs, t-butylphenyl diphenyl phosphate (BPDP), and bisphenol A bis(diphenyl phosphate) (BDP)] were quantified in urine and hair samples from children in Hong Kong, drinking water (tap water/bottled water) samples, and airborne particle samples from 17 kindergartens in Hong Kong. The results suggested that locally, children were exposed to various plasticizers and their alternatives. High concentrations of BPDP and BDP were present in urine, hair, tap water, bottled water, and air particulate samples. The geometric mean (GM) concentrations of phthalate metabolites in urine samples (126-2140ng/L, detection frequencies<81%) were lower than those detected in Japanese and German children in previous studies. However, a comparison of the estimated daily intake values for phthalates in tap water [median: 10.7-115ng/kg body weight bw/day] and air particles (median: 1.23-7.39ng/kgbw/day) with the corresponding reference doses indicated no risk. Bisphenol analogs were detected in 15-64% of urine samples at GM concentrations of 5.26-98.1ng/L, in 7-74% of hair samples at GM concentrations of 57.5-2390pg/g, in 59-100% of kindergarten air samples at GM concentrations of 43.1-222pg/m3, and in 33-100% of tap water samples at GM concentrations of 0.90-3.70ng/L. A significant correlation was detected between the concentrations of bisphenol F in hair and urine samples (r=0.489, p<.05). The estimated daily urinary excretion values of bisphenol analogs suggest that exposure among children via tap water intake and airborne particle inhalation in kindergartens cannot be ignored in Hong Kong.

Assessment of ambient aerosol sources in two important Atlantic Rain Forest hotspots in the surroundings of a megacity

Between 2010 and 2015, an assessment of ambient aerosol sources was carried in two unique fragments of the Atlantic Rain Forest in the surroundings of the Metropolitan Region of Rio de Janeiro (MRRJ). Airborne particulate matter samples were collected at Serra dos Órgãos National Park (43°04′42.1″W and 22°29′16.9″S) and Mário Xavier National Forest (43°42′21.8″W and 22°43′21.7″S). At the former site, PM10 samples were collected, while at the latter TSP samples were collected due to a particular interest on the preservation of an endangered endemic species of tree frog (Physalaemus soaresi). Elemental composition, inorganic and organic water-soluble compounds were analyzed along with local meteorology variables in order to provide the most relevant variables for particulate matter prediction and its potential sources. For TSP, the main predictors were NO3− >Mn >Rad (Global radiation) >Ca2+ >Precipitation >Mg 2+. For PM 10, the main predictors were Gust (Gust wind speed) >NO 3− >Ca2+ >Zn >Cu >Ti. Furthermore, trends in the particulate matter were analyzed considering the prevailing winds and sources were evaluated whether intermittent or continuous, using the conditional bivariate probability function (CBPF). With the use of CBPF, recent developed machine learning algorithms (Conditional inference trees – CIT, and Random Forests using a conditional inference framework), and other standard data analysis techniques tuned for air quality exercises, we provide an example case for planning and evaluation of environmental risk assessment by stakeholders.