scholarly journals Do Individuals’ Activity Structures Influence Their PM2.5 Exposure Levels? Evidence from Human Trajectory Data in Wuhan City

Author(s):  
Siyu Ma ◽  
Lin Yang ◽  
Mei-Po Kwan ◽  
Zejun Zuo ◽  
Haoyue Qian ◽  
...  

Severe air pollution has become a major risk to human health from a global environmental perspective. It has been recognized that human mobility is an essential component in individual exposure assessment. Activity structure reflects the characteristics of human mobility. Thus, a better understanding of the relationship between human activity structure and individual exposure level is of crucial relevance. This study examines this relationship using a large cell-phone GPS dataset in Wuhan, China. The results indicate that there is a strong linear relationship between people’s activity structures and exposures to PM2.5. Inter-group comparisons based on the four activity structure groups obtained with K-means clustering found that groups with different activity structures do experience different levels of PM2.5 exposure. Furthermore, differences in detailed characteristics of activity structure were also found at different exposure levels at the intra-group level. These results show that people’s activity structures do influence their exposure levels. The paper provides a new perspective for understanding individual exposure through human activity structure, which helps move the perspective of research on individual exposure from the semantic of physical location to the semantic of human activity pattern.

2019 ◽  
Vol 10 (1) ◽  
pp. 159 ◽  
Author(s):  
Jiyoung Woo ◽  
Guillaume Rudasingwa ◽  
Sungroul Kim

Particulate matters less than 2.5 micrometers in diameter (PM2.5), whose concentration has increased in Korea, has a considerable impact on health. From a risk management point of view, there has been interest in understanding the variations in real-time PM2.5 concentrations per activity in different microenvironments. We analyzed personal monitoring data collected from 15 children aged 6 to 11 years engaged in different activities such as commuting in a car, visiting a commercial building, attending an education institute, and resting inside home from October 2018 to March 2019. The fraction of daily mean exposure duration per activity was 72.7 ± 18.7% for resting inside home, 27.2 ± 14.4% for attending an education institute, and 11.5 ± 9.6% and 5.3 ± 5.9% for visiting a commercial building, commuting in a car, respectively. Daily median (interquartile range) PM2.5 exposure amount was 88.9 (55.9–159.7) μg in houses and that in education buildings was 43.3 (22.9–55.6) μg. Real-time PM2.5 exposure levels varied by person and time of day (p-value < 0.05). This study demonstrated that our real-time personal monitoring and data analysis methodologies were effective in detecting polluted microenvironments and provided a potential person-specific management strategy to reduce a person’s exposure level to PM2.5.


Author(s):  
Luca Scholz

Abstract: Borders and Freedom of Movement in the Holy Roman Empire tells the history of free movement in the Holy Roman Empire of the German Nation, one of the most fractured landscapes in human history. The boundaries that divided its hundreds of territories make the Old Reich a uniquely valuable site for studying the ordering of movement. The focus is on safe conduct, an institution that was common throughout the early modern world but became a key framework for negotiating free movement and its restriction in the Old Reich. The book shows that attempts to escort travellers, issue letters of passage, or to criminalize the use of ‘forbidden’ roads served to transform rights of passage into excludable and fiscally exploitable goods. Mobile populations—from emperors to peasants—defied attempts to govern their mobility with actions ranging from formal protest to bloodshed. Newly designed maps show that restrictions upon moving goods and people were rarely concentrated at borders before the mid-eighteenth century, but unevenly distributed along roads and rivers. In addition, the book unearths intense intellectual debates around the rulers’ right to interfere with freedom of movement. The Empire’s political order guaranteed extensive transit rights, but apologies of free movement and claims of protection could also mask aggressive attempts of territorial expansion. Drawing on sources discovered in more than twenty archives and covering the period between the late sixteenth to the early nineteenth century, the book offers a new perspective on the unstable relationship of political authority and human mobility in the heartlands of old-regime Europe.


Author(s):  
Danyang Sun ◽  
Fabien Leurent ◽  
Xiaoyan Xie

In this study we discovered significant places in individual mobility by exploring vehicle trajectories from floating car data. The objective was to detect the geo-locations of significant places and further identify their functional types. Vehicle trajectories were first segmented into meaningful trips to recover corresponding stay points. A customized density-based clustering approach was implemented to cluster stay points into places and determine the significant ones for each individual vehicle. Next, a two-level hierarchy method was developed to identify the place types, which firstly identified the activity types by mixture model clustering on stay characteristics, and secondly discovered the place types by assessing their profiles of activity composition and frequentation. An applicational case study was conducted in the Paris region. As a result, five types of significant places were identified, including home place, work place, and three other types of secondary places. The results of the proposed method were compared with those from a commonly used rule-based identification, and showed a highly consistent matching on place recognition for the same vehicles. Overall, this study provides a large-scale instance of the study of human mobility anchors by mining passive trajectory data without prior knowledge. Such mined information can further help to understand human mobility regularities and facilitate city planning.


Sensors ◽  
2020 ◽  
Vol 21 (1) ◽  
pp. 195
Author(s):  
Hua Chen ◽  
Ming Cai ◽  
Chen Xiong

With the rapid development of positioning techniques, a large amount of human travel trajectory data is collected. These datasets have become an effective data resource for obtaining urban traffic patterns. However, many traffic analyses are only based on a single dataset. It is difficult to determine whether a single-dataset-based result can meet the requirement of urban transport planning. In response to this problem, we attempted to obtain traffic patterns and population distributions from the perspective of multisource traffic data using license plate recognition (LPR) data and cellular signaling (CS) data. Based on the two kinds of datasets, identification methods of residents’ travel stay point are proposed. For LPR data, it was identified based on different vehicle speed thresholds at different times. For CS data, a spatiotemporal clustering algorithm based on time allocation was proposed to recognize it. We then used the correlation coefficient r and the significance test p-values to analyze the correlations between the CS and LPR data in terms of the population distribution and traffic patterns. We studied two real-world datasets from five working days of human mobility data and found that they were significantly correlated for the stay and move population distributions. Then, the analysis scale was refined to hour level. We also found that they still maintain a significant correlation. Finally, the origin–destination (OD) matrices between traffic analysis zones (TAZs) were obtained. Except for a few TAZs with poor correlations due to the fewer LPR records, the correlations of the other TAZs remained high. It showed that the population distribution and traffic patterns computed by the two datasets were fairly similar. Our research provides a method to improve the analysis of complex travel patterns and behaviors and provides opportunities for travel demand modeling and urban transport planning. The findings can also help decision-makers understand urban human mobility and can serve as a guide for urban management and transport planning.


2020 ◽  
Vol 185 (9-10) ◽  
pp. e1551-e1555
Author(s):  
Sean E Slaven ◽  
Benjamin M Wheatley ◽  
Daniel L Christensen ◽  
Sameer K Saxena ◽  
Robert J McGill

Abstract Introduction Noise exposure is an occupational health concern for certain professions, especially military servicemembers and those using power tools on a regular basis. The purpose of this study was to quantify noise exposure during total hip arthroplasty (THA) and total knee arthroplasty (TKA) cases compared to the recommended standard for occupational noise exposure. Materials and Methods A sound level meter was used to record cumulative and peak noise exposure levels in 10 primary THA and 10 primary TKA surgeries, as well as 10 arthroscopy cases as controls. Measurements at the distance of the surgeon were taken in all cases. In TKA cases, measurements were taken at 3 feet and 8 feet from the surgeon, to simulate the position of the anesthetist and circulating nurse, respectively. Results Time-weighted average was significantly higher in THA (64.7 ± 5.2 dB) and TKA (64.5 ± 6.8 dB) as compared to arthroscopic cases (51.1 ± 7.5 dB, P &lt; 0.001) and higher at the distance of the surgeon (64.5 ± 6.8 dB) compared to the anesthetist (52.9 ± 3.8 dB) and the circulating nurse (54.8 ± 11.2 dB, P = 0.006). However, time-weighted average was below the recommended exposure level of 85 dB for all arthroplasty cases. Peak levels did not differ significantly between surgery type or staff role, and no values above the ceiling limit of 140 dB were recorded. Surgeon’s daily noise dose percentage per case was 1.78% for THA and 2.04% for TKA. Conclusion Noise exposure in THA and TKA was higher than arthroscopic cases but did not exceed occupational standards. A daily dose percentage of approximately 2% per case indicates that repeated noise exposure likely does not reach hazardous levels in modern arthroplasty practice.


Author(s):  
Walder de Jesús Canova García

Resumen El creciente número de estaciones base de telefonía móvil celular alrededor de sectores residenciales o tránsito de personas, causa preocupación en la comunidad sobre si la radiación de campos electromagnéticos puedan causar riesgos en la salud. Internacionalmente existen estándares que establecen límites a las diversas fuentes de campos electromagnéticos para garantizar que se minimizan los riesgos en la salud. Cada país adopta dentro de su legislación algún estándar o recomendación y exige su cumplimiento a los operadores de estaciones de telecomunicaciones, por ejemplo en Colombia rige el decreto 195 de 2005. El artículo presenta una evaluación, basados en mediciones técnicas en el 2010, para obtener los niveles de exposición a campos electromagnéticos generados por las antenas instaladas en las estaciones base de telefonía móvil. Luego aparece el procedimiento general de mediciones, donde incluye el plan ejecutorial de mediciones, la configuración de la instrumentación y la caracterización de los lugares y puntos de medición. Por último, los resultados medidos en algunos lugares, donde las antenas de transmisión cumplían con la normativa adoptada en Colombia. Palabras Clave: Exposición a campos Electromagnéticos, Estaciones base de Telefonía móvil celular, Mediciones de banda angosta.   Abstract The growth of installations of transmitting antennas on base stations surrounding residential spaces or person traffic causes concerns in the community, about whether the radiation of electromagnetic fields of transmitting antennas in mobile base station can generate health risk. Over the world, there are standards that establish maximum levels permitted to different electromagnetic field sources to accomplish security ranges for health risks. Each country adopts in their legislation some international standard and requires to telecommunication operators stations for its compliance. In Colombian, the decree 195 of 2005 is still valid. This article shows an assessment, based on technical measurements developed in 2010, to acquire the electromagnetic field exposure levels generated by transmitting antennas installed on Mobile Base Station. This assessment includes the measurement system procedure: plan of measurement, instrumental configuration, and characterization of measurement places. Finally, here presents the measured results in some places, which exposure levels satisfied the adopted legislation in Colombia. Keywords: Electromagnetic Field Exposure, Mobile Base Stations, Narrowband Measurement.


2016 ◽  
Vol 26 (2) ◽  
pp. 226-237 ◽  
Author(s):  
Changsheng Cao ◽  
Jun Gao ◽  
Li Wu ◽  
Xihui Ding ◽  
Xu Zhang

This paper investigates the situation of residential kitchen ventilation and individual exposure in China and attempts to reduce the exposure through organizing local make-up airflow. Measurements were conducted in a kitchen chamber to reproduce the real exposure to the cooking-generated particles under the mode of natural make-up airflow surveyed. Measurements results show that an individual cooking in a kitchen could be exposed to a concentration of airborne particles at ∼10 mg/m3 within a simplified cooking process of oil heating, in the case of an experimental kitchen chamber with an open window or closed window/door. Local make-up airflow through upward make-up air supply or downward make-up air supply was further investigated to determine the effectiveness for reduction of the exposure level. When the air-supply velocity at the outlet of the upward make-up air supply or downward make-up air supply mode was well defined, the individual exposure level could be reduced by 2–3 orders of magnitude, as compared to the baseline case when all the make-up air was from open window. Intake fraction of cooking-generated particles could be as low as ∼10−5 and ∼10−6 under the two modes. This finding has illustrated that well-organized local make-up airflow could largely reduce an individual’s exposure to the cooking-generated particles in Chinese residential kitchen.


Author(s):  
G.A. Timerbulatova ◽  
◽  

Abstract: The unique physicochemical properties of carbon nanotubes allow them to be used in many fields. The global nanomaterials market is growing every year. An important step in introducing products to the domestic and world markets is to determine the safe exposure levels of CNTs. Establishing a corporate standard can serve as a preliminary stage before the approval of a state hygiene standard. Justification of the corporate standard is carried out in in vitro and in vivo experiments. The planning of experiments should be carried out taking into account the target organ under the influence of CNT - the respiratory system. The recommended dose / concentration range for experiments should include doses / concentrations derived from calculated and literature data. A necessary step is to obtain homogeneous dispersions in which CNTs become bioavailable for biological systems. During in vitro and in vivo experiments, the exposure level is determined at which no harmful effect is observed and / or the lowest level of exposure at which there is a harmful effect on the cell culture / respiratory tract of animals.


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