Personal Exposure Studies Research Articles

Characterization of spatial-temporal distribution and microenvironment source contribution of PM2.5 concentrations using a low-cost sensor network with artificial neural network/kriging techniques

Low-cost sensors (LCS) network is widely used to improve the resolution of spatial-temporal distribution of air pollutant concentrations in urban areas. However, studies on air pollution sources contribution to the microenvironment, especially in industrial and mix-used housing areas, still need to be completed. This study investigated the spatial-temporal distribution and source contributions of PM2.5 in the urban area based on 6-month of the LCS network datasets. The Artificial Neural Network (ANN) was used to calibrate the measured PM2.5 by the LCS network. The calibrated PM2.5 were shown to agree with reference PM2.5 measured by the BAM-1020 with R2 of 0.85, MNE of 30.91%, and RMSE of 3.73 μg/m3, which meet the criteria for hotspot identification and personal exposure study purposes. The Kriging method was further used to establish the spatial-temporal distribution of PM2.5 concentrations in the urban area. Results showed that the highest average PM2.5 concentration occurred during autumn and winter due to monsoon and topographic effects. From a diurnal perspective, the highest level of PM2.5 concentration was observed during the daytime due to heavy traffic emissions and industrial production. Based on the present ANN-based microenvironment source contribution assessment model, temples, fried chicken shops, traffic emissions in shopping and residential zones, and industrial activities such as the mechanical manufacturing and precision metal machining were identified as the sources of PM2.5. The numerical algorithm coupled with the LCS network presented in this study is a practical framework for PM2.5 hotspots and source identification, aiding decision-makers in reducing atmospheric PM2.5 concentrations and formulating regional air pollution control strategies.

Characterising sources of PM2·5 exposure for school children with asthma: a personal exposure study across six cities in sub-Saharan Africa

Air pollution is the second largest risk to health in Africa, and children with asthma are particularly susceptible to its effects. Yet, there is a scarcity of air pollution exposure data from cities in sub-Saharan Africa. We aimed to identify potential exposure reduction strategies for school children with asthma living in urban areas in sub-Saharan Africa. This personal exposure study was part of the Achieving Control of Asthma in Children in Africa (ACACIA) project. Personal exposure to particulate matter (PM) was monitored in school children in six cities in sub-Saharan Africa (Blantyre, Malawi; Durban, South Africa; Harare, Zimbabwe; Kumasi, Ghana; Lagos, Nigeria; and Moshi, Tanzania). Participants were selected if they were aged 12-16 years and had symptoms of asthma. Monitoring was conducted between June 21, and Nov 26, 2021, from Monday morning (approximately 1000 h) to Friday morning (approximately 1000 h), by use of a bespoke backpack with a small air pollution monitoring unit with an inbuilt Global Positioning System (GPS) data logger. Children filled in a questionnaire detailing potential sources of air pollution during monitoring and exposures were tagged into three different microenvironments (school, commute, and home) with GPS coordinates. Mixed-effects models were used to identify the most important determinants of children's PM2·5 (PM <2·5 μm in diameter) exposure. 330 children were recruited across 43 schools; of these, 297 had valid monitoring data, and 1109 days of valid data were analysed. Only 227 (20%) of 1109 days monitored were lower than the current WHO 24 h PM2·5 exposure health guideline of 15 μg/m3. Children in Blantyre had the highest PM2·5 exposure (median 41·8 μg/m3), whereas children in Durban (16·0 μg/m3) and Kumasi (17·9 μg/m3) recorded the lowest exposures. Children had significantly higher PM2·5 exposures at school than at home in Kumasi (median 19·6 μg/m3vs 14·2 μg/m3), Lagos (32·0 μg/m3vs 18·0 μg/m3), and Moshi (33·1 μg/m3vs 23·6 μg/m3), while children in the other three cities monitored had significantly higher PM2·5 exposures at home and while commuting than at school (median 48·0 μg/m3 and 43·2 μg/m3vs 32·3 μg/m3 in Blantyre, 20·9 μg/m3 and 16·3 μg/m3vs 11·9 μg/m3 in Durban, and 22·7 μg/m3 and 25·4 μg/m3vs 16·4 μg/m3 in Harare). The mixed-effects model highlighted the following determinants for higher PM2·5 exposure: presence of smokers at home (23·0% higher exposure, 95% CI 10·8-36·4), use of coal or wood for cooking (27·1%, 3·9-56·3), and kerosene lamps for lighting (30·2%, 9·1-55·2). By contrast, 37·2% (95% CI 22·9-48·2) lower PM2·5 exposures were found for children who went to schools with paved grounds compared with those whose school grounds were covered with loose dirt. Our study suggests that the most effective changes to reduce PM2·5 exposures in these cities would be to provide paving in school grounds, increase the use of clean fuel for cooking and light in homes, and discourage smoking within homes. The most efficient way to improve air quality in these cities would require tailored interventions to prioritise different exposure-reduction policies in different cities. UK National Institute for Health and Care Research.

A review of personal exposure studies in selected Asian countries' public transport microenvironments: lessons learned and future directions.

This comprehensive paper conducts an in-depth review of personal exposure and air pollutant levels within the microenvironments of Asian city transportation. Our methodology involved a systematic analysis of an extensive body of literature from diverse sources, encompassing a substantial quantity of studies conducted across multiple Asian cities. The investigation scrutinizes exposure to various pollutants, including particulate matters (PM10, PM2.5, and PM1), carbon dioxide (CO2), formaldehyde (CH2O), and total volatile organic compounds (TVOC), during transportation modes such as car travel, bus commuting, walking, and train rides. Notably, our review reveals a predominant focus on PM2.5, followed by PM10, PM1, CO2, and TVOC, with limited attention given to CH2O exposure. Across the spectrum of Asian cities and transportation modes, exposure concentrations exhibited considerable variability, a phenomenon attributed to a multitude of factors. Primary sources of exposure encompass motor vehicle emissions, traffic dynamics, road dust, and open bus doors. Furthermore, our findings illuminate the influence of external environments, particularly in proximity to train stations, on pollutant levels inside trains. Crucial factors affecting exposure encompass ventilation conditions, travel-specific variables, seat locations, vehicle types, and meteorological influences. The culmination of this rigorous review underscores the need for standardized measurements, enhanced ventilation systems, air filtration mechanisms, the adoption of clean energy sources, and comprehensive public education initiatives aimed at reducing pollutant exposure within city transportation microenvironments. Importantly, our study contributes to the growing body of knowledge surrounding this subject, offering valuable insights for policymakers and researchers dedicated to advancing air quality standards and safeguarding public health.

Long-term field calibration of low-cost metal oxide VOC sensor: Meteorological and interference gas effects

This study aimed to evaluate the performance of the Sensirion SGP30 MOS (metal oxide semiconductor) VOC sensors (SMVSs) for a long sampling period (10–12 months) at different ambient air monitoring stations (AQMSs). In the field tests, temperature (T), relative humidity (RH), carbon monoxide (CO) concentration, and non-methane hydrocarbons (NMHC) concentrations were found to be the crucial parameters influencing the sensor readings. A multiple linear regression (MLR) calibration model using hourly T, RH, CO, and VOC values as parameters was developed at Zhongming (ZM) station and validated at Hsinchu (HC) and Tainan (TN) stations. After calibration, the SMVS performance was improved significantly with the decrease of mean normalized bias (MNBs) and mean normalized errors (MNEs) of hourly-average data from +228 to 473% to ±25.9% and 231–473%–47.2%, respectively based on the reference NMHC values in the AQMSs. For ambient NMHC concentrations higher than 100 ppbv, the MLR-calibrated results were further improved with MNBs (MNEs) less than ±20% (28.3%). The correlation between calibrated sensor data and reference data was enhanced significantly with the R2 values increasing from 0.27 to 0.50 to 0.65–0.78 at three stations. Therefore, these well-calibrated sensors can become viable tools for many purposes including hotspot identification and characterization, and personal exposure study (MNE<30%).

Abstract P3-03-06: A pilot study of personal care product use and exposure to environmental chemicals among Black and Hispanic breast cancer survivors

Abstract Objectives and rationale: Racial and ethnic minorities are disproportionately exposed to environmental chemicals that have been linked to cardiovascular disease, cognitive decline, metabolic disease, and premature mortality. Recent evidence suggests that personal care products are a source of such exposures and that these products are more frequently used among Black and Hispanic women. Minoritized populations also tend to experience worse breast cancer outcomes compared to White patients. However, few studies have examined personal care product use and environmental exposures among minority cancer survivors. The aim of the present study was to describe personal care product use and chemical exposures, including ambient and dermal sources of exposure, in a pilot study of Black and Hispanic breast cancer survivors. Methods: In November 2020 – December 2021, self-identified Black and Hispanic breast cancer survivors aged ≥21 years were recruited in Washington, DC and Hackensack, NJ. Eligible survivors had been diagnosed with primary Stage I-III breast cancer and had completed breast cancer treatment except endocrine therapy. Surveys collected data on demographics, breast cancer diagnosis, personal care product use, and potential covariates. Participants wore silicone wristbands for 1 week for passive sampling of environmental exposures. Extracts from the wristbands were assessed using a gas chromatograph-mass spectrometer to detect chemical exposures. Values were adjusted for wear time and wristband size to provide sample concentrations of detected chemicals. Results: Among the 25 study participants, 17 were Black and 8 were Hispanic, with a mean age of 58 years. Most survivors (58%) had been diagnosed with Stage I breast cancer. Survivors reported using perfume (52%), make-up (80%), and nail polish (68%) during the week, with common daily use of facial creams, lotions, or moisturizers (60%) and body creams, lotions, or moisturizers (68%). Drinking bottled water every day (64%) or most days (24%); eating prepared food from a fast food restaurant at least once per week (88%); and eating food reheated in a plastic container at least once per week (71%) were also prevalent. However, the majority of survivors reported never using pesticides indoors (76%) or outdoors (79%). The wristbands detected 60 distinct chemicals. On average, 21.8 chemicals were detected per wristband and 19 chemicals were detected in more than half of the samples. Exposure to flame retardants and pesticides was ubiquitous. All participants were exposed to chemicals found in personal care products and in commercial products. Several of the most commonly detected chemicals, including benzyl salicylate (a UV light absorber and fragrance), diisobutyl phthalate (a plasticizer), and lilial (a perfume), are biologically active compounds with potential genotoxic or endocrine effects. Discussion: Exposure to environmental chemicals was ubiquitous among Black and Hispanic breast cancer survivors in DC and New Jersey. Frequent use of personal care products and commercial products suggest an opportunity to reduce potentially harmful exposures. Future studies are needed to investigate the role of environmental chemicals in health outcomes among breast cancer survivors and whether environmental exposures contribute to cancer health disparities. Citation Format: Traci N. Bethea, Jennifer Hicks, Erin Speiser, Adana Llanos, Gail E. Starr, Chiranjeev Dash, Lucile L. Adams-Campbell. A pilot study of personal care product use and exposure to environmental chemicals among Black and Hispanic breast cancer survivors [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P3-03-06.

Deposition effect of inhaled particles in the human: Accurate health risks of personal exposure to PAHs and their derivatives from residential solid fuel combustion

The drastic household clean heating renovation has been undertaken in rural northern China since 2017. A method incorporating the deposition efficiency of particulate matters (PMs) in the human respiratory tract is firstly introduced into the personal exposure (PE) study which is more accurately assess the health risks of homemakers inhaling PM-bound four subclasses polycyclic aromatic hydrocarbons (PAHs) emitted from different solid fuels (i.e., biomass, raw coal chunk, and clean coal). Homemakers using clean coal show the lowest exposure levels of all PAH subclasses (parent, alkylated, oxygenated, and nitro PAHs) and total quantified PAHs (ΣPAHs). Remarkable reductions of 93.9% and 89.0% on ΣPAHs in PE PM2.5 are observed with the substitutions of the raw coal chunk and biomass fuel by the clean coal, respectively. 86.8–96.8% of ΣPAHs are inhaled by the human body, while approximately 22.4–44.8% are deposited in the respiratory tract. The deposition concentrations (DC) of ΣPAHs in the biomass and raw coal chunk groups are 12 and 5 times the clean coal group, respectively. PAHs in coarse mode PE particles with an aerodynamic size between 2.5 and 100 μm mostly deposit in the head airway (HA) (98%). Moreover, the PAHs in fine particles (i.e., with aerodynamic size less than 2.5 μm) mainly deposit in the alveolar region (AR), accounting for 20–70% of ΣPAHs. Replacing biomass and raw coal chunk with clean coal reduced incremental lifetime cancer risks (ILCR) by 91% and 92%, respectively. This study improves the understanding of the PM-bound PAHs deposition in the human respiratory system and contributes to the promotion of domestic energy transition in rural northern China.

Individual level spatial-temporal modelling of exposure potential of livestock in the Cove Wash watershed, Arizona

ABSTRACT Personal exposure studies suffer from uncertainty issues, largely stemming from individual behaviour uncertainties. Built on spatial-temporal exposure analysis and methods, this study proposed a novel approach to spatial-temporal modelling that incorporated behaviour classifications taking into account uncertainties, to estimate individual livestock exposure potential. The new approach was applied in a community-based research project with a Tribal community in the southwest United States to address questions on potential livestock exposure to abandoned uranium mines (AUMs). The study aimed to 1) classify Global Positioning System (GPS) data from livestock into three behaviour subgroups – grazing, travelling or resting; 2) calculate the daily cumulative exposure potential for livestock; 3) assess the performance of the computational method with and without behaviour classifications. Using Lotek Litetrack GPS collars, we collected data at a 20-min-interval for two flocks of sheep and goats during the spring and summer of 2019. Analysis and modelling of GPS data demonstrated no significant difference in individual cumulative exposure potential within each flock when animal behaviours with probability/uncertainties were considered. However, when daily cumulative exposure potential was calculated without consideration of animal behaviour or probability/uncertainties, significant differences among animals within a herd were observed, which does not match animal grazing behaviours reported by livestock owners. These results suggest that the proposed method including behaviour subgroups with probability/uncertainties more closely resembled the observed grazing behaviours. Results from the research may be used for future intervention and policy-making on remediation efforts in communities where grazing livestock may encounter environmental contaminants.

An Investigation into Which Methods Best Explain Children's Exposure to Traffic-Related Air Pollution.

There have been several methods employed to quantify individual-level exposure to ambient traffic-related air pollutants (TRAP). These include an individual’s residential proximity to roads, measurement of individual pollutants as surrogates or markers, as well as dispersion and land use regression (LUR) models. Hopanes are organic compounds still commonly found on ambient particulate matter and are specific markers of combustion engine primary emissions, but they have not been previously used in personal exposure studies. In this paper, children’s personal exposures to TRAP were evaluated using hopanes determined from weekly integrated filters collected as part of a personal exposure study in Windsor, Canada. These hopane measurements were used to evaluate how well other commonly used proxies of exposure to TRAP performed. Several of the LUR exposure estimates for a range of air pollutants were associated with the children’s summer personal hopane exposures (r = 0.41–0.74). However, all personal hopane exposures in summer were more strongly associated with the length of major roadways within 500 m of their homes. In contrast, metrics of major roadways and LUR estimates were poorly correlated with any winter personal hopanes. Our findings suggest that available TRAP exposure indicators have the potential for exposure misclassification in winter vs. summer and more so for LUR than for metrics of major road density. As such, limitations are evident when using traditional proxy methods for assigning traffic exposures and these may be especially important when attempting to assign exposures for children’s key growth and developmental windows. If long-term chronic exposures are being estimated, our data suggest that measures of major road lengths in proximity to homes are a more-specific approach for assigning personal TRAP exposures.

User-Centred Design of a Final Results Report for Participants in Multi-Sensor Personal Air Pollution Exposure Monitoring Campaigns.

Using low-cost portable air quality (AQ) monitoring devices is a growing trend in personal exposure studies, enabling a higher spatio-temporal resolution and identifying acute exposure to high concentrations. Comprehension of the results by participants is not guaranteed in exposure studies. However, information on personal exposure is multiplex, which calls for participant involvement in information design to maximise communication output and comprehension. This study describes and proposes a model of a user-centred design (UCD) approach for preparing a final report for participants involved in a multi-sensor personal exposure monitoring study performed in seven cities within the EU Horizon 2020 ICARUS project. Using a combination of human-centred design (HCD), human–information interaction (HII) and design thinking approaches, we iteratively included participants in the framing and design of the final report. User needs were mapped using a survey (n = 82), and feedback on the draft report was obtained from a focus group (n = 5). User requirements were assessed and validated using a post-campaign survey (n = 31). The UCD research was conducted amongst participants in Ljubljana, Slovenia, and the results report was distributed among the participating cities across Europe. The feedback made it clear that the final report was well-received and helped participants better understand the influence of individual behaviours on personal exposure to air pollution.

Long-term evaluation and calibration of three types of low-cost PM2.5 sensors at different air quality monitoring stations

To evaluate the performance of low-cost PM2.5 sensors and develop calibration models for correcting for the PM2.5 sensor data (PM2.5,S), field comparison tests were conducted based on Met One BAM-1020 data at various locations using long-term (≥one year) data of Plantower PMS5003, Sensirion SPS30, and Honeywell HPMA115S0 PM2.5 sensors. Both multivariate linear regression (MLR) and non-linear regression (NLR) models using hourly RHs and original sensor PM2.5 data as parameters were able to obtain accurate calibrated hourly PM2.5 values with MNBs (mean normalized biases) less than about ±10% and MNEs (mean normalized errors) less than about 30% for all three types of PM2.5 sensors at all monitoring locations. On the other hand, the MNB and MNE of the calibrated 24-hr average PM2.5 data for the two models were less than ±13% and 20%, respectively. Moreover, the slope, intercept, and R2 of the linear regression line of the calibrated 24-hr average PM2.5 and BAM-1020 data were as good as 1.0 ± 0.1, 0.0 ± 2.0 μg/m3, and ≥0.88, respectively. Therefore, these well-calibrated sensors can well be served for education and information (MNE<50%), hotspot identification and characterization (MNE<30%), and personal exposure study (MNE<30%) purposes, and even supplement the existing daily PM2.5 data of the air quality monitoring stations (MNE<20%).

Fine particulate matter exposure in four transport modes of Greater Cairo

The number of daily commuters in Greater Cairo has exceeded 15 million nevertheless personal exposure studies in transport microenvironments are limited. The aim of this study is to quantify PM2.5 exposure during peak hours in four transport modes of Greater Cairo - car (windows-open, windows-closed with recirculation and AC-on), microbus (windows-open), cycling and walking - and understand its underlying drivers. Data was collected using a pDR-1500 monitor and analysed to capture concentration variations, spatial variability, exposure doses, commuting costs versus inhaled doses, health burden and economic losses. Car with recirculation resulted in the least average PM2.5 concentrations (32 ± 6 μg/m3), followed by walking (77 ± 35 μg/m3), car with windows-open (82 ± 32 μg/m3), microbus with windows-open (96 ± 29 μg/m3) and cycling (100 ± 28 μg/m3). Evening hours observed average PM2.5 concentrations by 26–58% lesser than morning. Spatial variability analysis showed that 75th–90th percentile PM2.5 concentrations coincided with congested spots. Cycling and walking lanes are rare hence commuters are exposed to surges in PM2.5 concentrations when passing near construction and solid waste burning sites. Cycling and walking also resulted in inhaling 40-times and 32-times higher PM2.5 dose per kilometre than for car with recirculation. Commuting by microbus cost (with windows-open) ~45% of car cost (with recirculation) but it resulted in 4-times higher inhaled PM2.5 dose. As expected due to the lowest PM2.5 exposure concentrations, health burden resulting from car travel (with recirculation) caused the least death rates of 0.07 (95% CI 0.07–0.08) prematures deaths per 100,000 commuters/year while microbus with windows-open resulted in the highest death rates; 0.52 (95% CI 0.49–0.56). Microbus deaths represent 57% of national economic losses due to PM2.5 exposure amongst the four transport modes. This study provides real-time exposure data and analyses its implications on commuter health as a first step in informed decision-making and better urban planning.

Wi-fi related radiofrequency electromagnetic fields (RF-EMF): a pilot experimental study of personal exposure and risk perception

The impact of providing people with an objectively measured personal radiofrequency electromagnetic fields (RF-EMF) exposure information on the risk perception of people is not well understood. We conducted an experimental study, among three groups of participants, to investigate the risk perception of people towards RF-EMF from Wi-Fi sources (ISM 2.4 GHz) by providing participants with either basic text, precautionary information, or a summary of their personal RF-EMF exposure measurement levels. Participants provided with personal RF-EMF exposure measurement information were more confident in protecting themselves from RF-EMF exposure, compared to those provided with only basic information. Nonetheless, neither the exposure perception nor the risk perception of people to Wi-Fi related RF-EMF differed by the type of information provided. The measured Wi-Fi signal levels were far below international exposure limits. Furthermore, self-rated levels of personal RF-EMF exposure perception were not associated with objectively measured RF-EMF exposure levels. Providing people with objectively measured information may help them build confidence in protecting themselves from Wi-Fi related RF-EMF exposure.

Ultrafine particles, psychosocial stress, and sleep: new epidemiological links?

Introduction: Insufficient or poor-quality sleep during childhood is common and can have lifelong adverse health effects. Ultrafine particle (UFP) exposure and psychosocial stress can impact cardiovascular, respiratory, and neurological health but the effects of UFPs, particularly among children experiencing psychosocial stress, on sleep outcomes are unknown.Methods: This study includes 118 adolescents from the Ecologocial Momentary Assessment and Personal particle Exposure (EcoMAPPE) Study. A seven-day sampling period using a personal UFP monitor was completed and average daily concentrations of UFP were calculated. PROMIS® pediatric self-report measures were used to assess elevated levels (T-scores ≥ 60) of anxiety and depression symptoms over the sampling period. At the end of the sampling period, the child completed the Sleep Habits Questionnaire (SHQ); outcomes included sleep duration and frequency of night waking. Regression models were used to assess the associations between an IQR increase in UFP exposure and sleep outcomes and explore effect modification by concurrent psychosocial stress.Results: Increased UFP exposure was marginally associated with shorter weekend sleep duration (β = -0.43, SE 0.23, p=0.07); UFP exposure was not associated with night waking. Among children reporting elevated anxiety symptoms, UFP exposure was associated with reduced sleep duration during the week (β=-1.01, SE=0.49, pUFP*anxiety=0.04) and weekend (β=-1.65, SE=0.71, pUFP*anxiety=0.01). Among children experiencing elevated depression symptoms, increased UFP exposure was significantly associated with reduced sleep duration during the weekend (β=-2.09, SE=0.81, pUFP*depression=0.009). All models controlled for child’s age, race, gender, asthma status, maternal education, and exposure to environmental tobacco smoke.Conclusions: Exposure to UFPs alone does not result in poor quality sleep; however, concurrent UFP exposure and symptoms of anxiety/depression may have a negative impact on sleep outcomes. Understanding the potential synergistic effects between psychosocial factors and environmental toxins (e.g., UFP) will help inform health risks related to poor sleep outcomes among adolescents.

Acute cardiovascular health effects in a panel study of personal exposure to traffic-related air pollutants and noise in Toronto, Canada

Urban populations are often simultaneously exposed to air pollution and environmental noise, which are independently associated with cardiovascular disease. Few studies have examined acute physiologic responses to both air and noise pollution using personal exposure measures. We conducted a repeated measures panel study of air pollution and noise in 46 non-smoking adults in Toronto, Canada. Data were analyzed using linear mixed-effects models and weighted cumulative exposure modeling of recent exposure. We examined acute changes in cardiovascular health effects of personal (ultrafine particles, black carbon) and regional (PM2.5, NO2, O3, Ox) measurements of air pollution and the role of personal noise exposure as a confounder of these associations. We observed adverse changes in subclinical cardiovascular outcomes in response to both air pollution and noise, including changes in endothelial function and heart rate variability (HRV). Our findings show that personal noise exposures can confound associations for air pollutants, particularly with HRV, and that impacts of air pollution and noise on HRV occur soon after exposure. Thus, both noise and air pollution have a measurable impact on cardiovascular physiology. Noise should be considered alongside air pollution in future studies to elucidate the combined impacts of these exposures in urban environments.

Technology development of breathing thermal manikin and its application and prospect in healthy building

The core concept of healthy building is “people-oriented”. Indoor environment directly affects human health, comfort level, and work efficiency. The intuitive feeling and health effects of indoor occupants should be key evaluation indicators in constructing indoor environment. However, limited by existing experimental methods, testing techniques, and ethical considerations, many experiments related to indoor human health and comfort cannot be carried out on human bodies. In addition, although existing indoor environmental monitoring techniques and equipments can meet parameter control and energy efficiency requirements, they are relatively independent, and have not been integrated on a comprehensive platform. Furthermore, indicators are needed to reflect the comprehensive influence of multiple environmental parameters on the health effects of occupants. Therefore, in order to evaluate human thermal comfort in different environments and determine the effective doses of pathogenic sites in personal exposure studies, advanced and reliable measurement tools must be developed first. As a sophisticated and complex device, thermal manikin plays an important role in the evaluation of indoor health effects. It was originally used to measure and evaluate clothing performance parameters; with the development of control methods and manufacturing technology, many scholars have put forward sweating thermal manikin, thermal regulation manikin, and breathing thermal manikin on the basis of clothing thermal manikin. This paper systematically reviews the progress of research in three aspects, that is, the development history of thermal manikin, the construction of human microenvironment, and the construction of in vitro respiratory tract model. In different development stages and application environments, the implementation method, functions, features, and control methods of thermal manikin show diversity, but its implementation principles are basically similar. That is, it consists of morphological shell, surface skin, heating element, and sensor. The manikin’s structural characteristics and surface thermal plumes seriously affect the human micro-environment. Based on the latest research progress in the field of personal exposure, this paper summarizes the characteristics of flow field and the influencing factors of pollutant exposure in human micro-environment under experimental conditions with varying degrees of human model simplification. After that, it discusses the current status and difficulties of research on human inhalation exposure, and explains the significance of CT scanning, 3D printing, in vitro cell culture, and organ chip technology in the establishment of dose-effect relationship model, as well as their applications in the targeted therapy and biomarker research of lung diseases. On this basis, it talks about the development prospects of health effect research using a thermal manikin that has integrated 3D printing technology and breathing simulation function. This paper systematically reviews the research progress and applications of breathing thermal manikin and various advanced lung models in the fields of building environment and human health. Starting from airflow creation in human micro-environment, in vitro respiratory tract model, in vitro cell culture, and organ chip construction, it sums up the latest research progress of thermal manikin, draws the main conclusions of this field, presents the vision of the future prospects, and points out the limitations and shortcomings in this area. This paper aims to promote the development of more reasonable and accurate environmental control techniques, achieve healthy building, and promote the progress of pathology, pharmacology, and other disciplines.

Portable multi-sensor air quality monitoring platform for personal exposure studies

Poor air quality is considered among the main causes of millions of premature deaths annually, about 8 million in 2012 according to the World Health Organization [1]. Several epidemiological studies have found a relationship between exposure beyond specified limits and burden of disease [2]. These and many more have led to an increased and urgent need to both monitor and consequently limit personal exposure to harmful pollutants [3]. There is a generalized attention from different governmental agencies globally to limit anthropogenic emissions via legislations and policies. City councils, including for instance in Cambridge, UK, promote new policies that help accelerate switching from combustion engines to electric vehicles both for public and for private transport, accompanied by installation of a distributed urban network of rapid charging points by 2020 [4], along with imposition of road taxes, and exemption from the same based on vehicles' emission of polluting gases and smaller particulate matter (PM2.5). Besides, reduction of indoor wood burning for heating, as one of the largest sources of indoor particulate matter, also has the potential to drastically reduce PM2.5 exposure levels. Citizens are nowadays more conscious of and attentive to their personal exposure to polluting agents and environments and prone to adopt cleaner solutions for living, transport, energy generation and heating. Adoption of personal exposure monitoring devices on an individual level therefore offers multiple benefits and is motivated by the willingness to continue making healthier choices in everyday life consistently. Access to high resolution data of personal exposure with high space and time accuracy is however difficult to achieve with currently available centralized or public network of monitoring stations. Providing individuals with portable devices for air quality monitoring that operate in real time and allow them to monitor and record their personalized exposure levels in combination with conventional geolocation offering a half-meter or less space resolution may become a unique instrument and breakthrough, not only for the individuals, but also for the city councils, and other government agencies to shape and fine-tune their policies for control of air quality in urban, industrial and rural areas. This is possible with the use of both existing and emerging technologies for autonomous sensors, data communication and modern mobile networks, including Internet of Things.

Performance Test of MicroAeth® AE51 at Concentrations Lower than 2 μg/m3 in Indoor Laboratory

It is difficult to find information about how the microAeth® AE51 performs, in spite of its versatility for about a decade in various research fields such as black carbon measurements and personal exposure studies. Stimulated by this, we conducted real-time tests for indoor aerosol in order to provide performance characteristics toward proper usage. We calculated the attenuation (ATN) using the reference signal together with the sensing signal to compare it with the ATN recorded in a microAeth® AE51. Performance was evaluated under extremely low concentration through the zero test, using filtered clean air. Ten-day-long continuous measurements were done for both indoor aerosol and filtered particle free air to examine the feasibility of microAeth® AE51 in an indoor use. Generally, MicroAeth® AE51 exhibited excellent performance, though it showed relatively low performance under some conditions. Noise was intensified while it was directly connected to a power adaptor. Another issue includes the occurrence of negative concentrations for extremely clean air. The noise amplification turned out to be related to a power source independent on the internal battery, and it was able to be removed by post-processing. Uncertainty analysis was carried out to better understand the origin of unwanted noise. Technical perspective of a proper usage will be addressed with regard to what will play a role for a long-term monitoring.

Assessment of Microenvironmental Exposures to Ultrafine Particles among Adolescent Schoolchildren

Background: Assessing personal exposure to ultrafine particles (UFPs) is challenging due to multiple indoor and outdoor sources and high spatiotemporal variation. Our objective is to characterize personal UFP exposures experienced by adolescents enrolled in the Ecological Momentary Assessment and Personal Particle Exposure Study (EcoMAPPE). Methods: Participants (ages 13-17) complete a seven-day sampling period using a personal UFP monitor for 3 hours each day that simultaneously records GPS-based location at 1-second resolution. Measured UFP concentrations are assigned to microenvironments based on speed and distance from participant specified locations: schools (400m), homes (100m), and other (100m) locations. UFP concentrations measured outside these areas exhibiting speeds greater than 2 m/s are categorized as occurring while in transit. We define the percent contribution of each microenvironment to a participant&amp;#8217;s overall exposure as the summation of UFP concentration in a specific microenvironment divided by the summation of all recorded UFP concentrations. Lastly, we derive exposure-time ratios by dividing the percent contribution of each microenvironment by the percentage of time spent within each microenvironment. Results: Complete sampling and location data is available for 21 participants, representing 378.5 hours of UFP data. The overall median UFP concentration is lowest at home (4,500 particles/cm3), while school/other (5,990), and transit concentrations (7,960) are higher. Most UFP measurements are recorded at home (70%), followed by school/other locations (23%), and transit (7%). Participants experience median exposure-time ratios of 0.99 (Q1: 0.90; Q3: 1.04) at home, 0.82 (0.45; 1.21) at other locations, and 1.10 (0.62; 1.73) in transit.Conclusion: Despite the low percentage of time spent in transit, most participants experience UFP concentrations during transit that contribute more to their overall exposure in comparison to other microenvironments.

Advanced Smartphone-Based Sensing with Open-Source Task Automation.

Smartphone-based sensing is becoming a convenient way to collect data in science, especially in environmental research. Recent studies that use smartphone sensing methods focus predominantly on single sensors that provide quantitative measurements. However, interdisciplinary projects call for study designs that connect both, quantitative and qualitative data gathered by smartphone sensors. Therefore, we present a novel open-source task automation solution and its evaluation in a personal exposure study with cyclists. We designed an automation script that advances the sensing process with regard to data collection, management and storage of acoustic noise, geolocation, light level, timestamp, and qualitative user perception. The benefits of this approach are highlighted based on data visualization and user handling evaluation. Even though the automation script is limited by the technical features of the smartphone and the quality of the sensor data, we conclude that task automation is a reliable and smart solution to integrate passive and active smartphone sensing methods that involve data processing and transfer. Such an application is a smart tool gathering data in population studies.

Personal Exposure to PM2.5 in the Various Microenvironments as a Traveler in the Southeast Asian Countries

Air pollution has become a pressing issue in today’s society because of its significant effects on humans, animals, plants, air quality, climate and the wider environment. Most urban areas are associated with one or more air pollutants which are emitted from local or regional pollution sources including vehicle exhausts, fossil fuels using in energy production, emissions from industrial and mining activities, agricultural and construction operations, household usage of chemicals and materials and natural causes. Most personal exposure studies are focused on local environments and short-term periods. Previous controlled experiments and studies were done in a small number of designated areas in cities. Our research study used time-based activity data; 3 main and 17 sub-microenvironments were applied over 37 days-long research while traveling through Southeast Asian countries. In this study, personal exposure of PM2.5 for a traveler was monitored using an assembled low-cost monitor with Plantower PMS 3003 PM2.5 sensor which has a light-scattering principle. All time-based activity data was recorded with a smartphone whenever microenvironments changed during the study period. The goal of this study was to understand more about the personal exposure to PM2.5 related air pollution in the global travel environment as a traveler and to understand how an individual’s activity and location impact PM2.5 exposure. According to the results from the Southeast Asia study, the personal PM2.5 exposure varied in the categorized microenvironments. Port/Station (outdoor) and Cafe/Pub/Restaurant (indoor-outdoor) were the most polluted microenvironments with 32.8 and 29.6 µg/m3 1-h mean PM2.5 concentration, respectively. Market/Shopping Mall (indoor), Street (outdoor) and Cable Car/Metro/Tram (vehicle) were also concerning microenvironments with 19.3, 19.3 and 18.9 µg/m3 1-h mean PM2.5 concentrations, respectively. Passenger Car microenvironment had the lowest 1-h mean PM2.5 concentration of 2.3 µg/m3 which agrees with some other studies on transportation microenvironments in the literature.