Medium Population Density Research Articles

Do mobile applications foster sustainable mobility? Evidence from a field experiment

Mobile applications hold promise to foster sustainable mobility behavior, but evaluations of their effectiveness are subject to a number of empirical challenges. We conduct a randomized controlled trial with three distinctive features: unobtrusive tracking of the control group, limited sample attrition, and a representative sample. In our study, 410 participants track their mobility behavior over a 5 week period. After 1 week, the treatment group engages with the user interface of the “Swiss Climate Challenge App”. The user interface combines information on individual CO2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\hbox {CO}_2$$\\end{document} emissions with gamification features. We find a treatment effect that implies a 9.8%\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$9.8\\%$$\\end{document} reduction in emissions caused by access to the mobile application. While we lack the statistical power to exclude a zero average effect, we find statistically significant emission reductions in the second half of the intervention period, among subjects in medium population density areas, and among men. Our findings suggest that mobile applications could generate considerable net benefits, but larger studies will be needed for validation.

Negative exokarstic units as a basis for urban management: Yucatan Peninsula, Mexico

The morphometric characterization of large-scale depressions, with high-resolution contributions and in urban contexts, has been carried out in the cities of Cozumel and Playa del Carmen. For Tulum, the inputs have been insufficient in identifying depressions at a detailed level. This research aimed to analyze and characterize the negative exokarstic relief of the city of Tulum through morphometric parameters and urban elements that contribute to the knowledge of the human-nature relationship. From the DEM ALOS PALSAR, contour lines, elevation models, slopes, and shadows were extracted, which allowed the identification of depressions, topographic profiles, and the calculation of morphometric indices; subsequently, the distribution of depressions was analyzed concerning urban elements. The identified depressions were classified into uvalas, sinkholes, and poljes. The analysis of the topographic profiles allowed us to recognize units in the shape of "V" (64%), "U" (19%), and "Hoya" (17%). The highest concentration of type V depressions is observed in the city's central area, characterized by a medium and high population density, as well as the centralization of commercial and public establishments. The detailed characterization of depressions is a planning and management tool for the territory.

Not population density, but city size and per capita income influence the urban forest carbon sequestration: A case of growing cities in Arkansas, USA

While urban trees provides significant ecosystem services, the impact of increasing urbanization and population on their carbon sequestration potential remains relatively underexplored in interior sprawling cities, highlighting a critical research gap amid growing urban environmental challenges. Although existing studies suggest a strongly correlation between urban forest cover and carbon sequestration, this study aims to investigate how the urban demography factors influence land cover and carbon sequestration across cities with low, medium, and high population densities. Using the i-Tree Canopy tool, we sampled 18,814 random points to estimate city land cover and carbon sequestration in Arkansas, interior state of the US. Results from the principal component analysis revealed that 74% of the variation in a city's land cover among population density classes is attributed to tree and soil cover percentages. The mean annual (1.40 ± 0.08 T ha-1) and total carbon sequestration rates (35.30 ± 5.57 T ha-1) were significantly higher in the areas with low population density due to a higher average tree cover percentage (46%). Carbon sequestration rate was negatively associated with land cover types such as impervious surfaces like buildings (r = -0.44), roads (r = -0.28), grass cover (r = -0.46), and impervious other (r = -0.53). The log-linear model with scaled variables suggested that factors such as city's size and tree cover has positive influence urban trees' annual and total carbon sequestration, while spatial distribution and per capita income negatively affect these ecosystem befits in growing cities, regardless of population density. Travel time within city may have negative impact, while decadal population change may positively impact on carbon sequestration alongside management effort. Valuing this potential urban forest carbon sequestration for emerging carbon market could provide monetary benefits to the urban communities, city managers, and policymakers, enabling the development of effective urban forest management strategies in the context of urban climate change.

Effect of plant architecture on the responses of canopy temperature and water use to population density in winter wheat

AbstractRevealing how plant architecture affects the responses of canopy temperature depression (CTD), water use (WU), and grain yield to population density (PD) in wheat (Triticum aestivum L.) would help explore a water‐saving pathway related to managing population. This study was conducted over three consecutive years under rainfed and supplemental irrigation conditions. The flat‐leafed Jinmai 47 and upright‐leafed Jing 411 genotypes were grown at high population density (HD), medium population density (MD), and low population density (LD); seeding rates were 450, 675, and 900 seeds m−2, respectively). CTD peaked at MD in Jinmai 47 but reached the highest at HD in Jing 411. WU generally increased with increasing PD but remained unchanged from LD to MD in Jinmai 47 under the two water conditions, while it remained unchanged from MD to HD under supplemental irrigation condition in Jing 411. Yield increased with increasing density in both genotypes under the two water conditions. It is thus clear that Jinmai 47 gained higher yield but did not consume more water at MD than at LD under the two water conditions; Jing 411 obtained higher yield at the expense of similar amount of water at HD than at MD under supplemental irrigation condition. The grain yield and WU responses of wheat crops to PD implied that through appropriately adjusting PD in combination with plant architecture and water condition, the dual goals of optimizing yield and effectively saving irrigation water could be realized synchronously.

The distribution structure of medical and care resources based on regional characteristics throughout Japan in 2020

BackgroundGiven Japan’s rapidly aging population, the Ministry of Health, Labour and Welfare's policy of reducing hospital beds and replacing medical care with nursing care requires the establishment of a coordinated system of medical and care services tailored to regional characteristics. To gain useful knowledge for the development of such a system, this study aimed to identify differences in the structure of the relationship between medical and care resources due to differences in regional characteristics.MethodsInitially, regional characteristics were used to group all 334 secondary medical areas (SMA) in Japan by principal component analysis. Subsequently, the related structure of the distribution of medical and care resources for each group were compared. For these comparisons, first, the related structure of the distribution of medical and care resources nationwide was modeled using structural equation modeling. Secondly, multigroup analysis was conducted to investigate differences among the models across groups.ResultsThe nationwide SMAs were grouped largely based on urbanicity and middle-density regionality. The groups with high urbanicity and high middle-density regionality consisted of SMAs with a high and medium population density. By contrast, the low middle-density regionality group consisted of SMAs containing large cities with a high population density and depopulated areas with a low population density. The model of the related structure of the distribution of medical and care resources differed among these groups. In the non-urbanicity and middle-density regionality groups, nursing care abundance tended to increase acute care abundance. In addition, in all groups, nursing care abundance tended to increase long-term hospitalization care abundance and clinic care abundance (with beds).ConclusionsThe key finding of this study was that the government’s objective of reducing hospital beds may not be achieved solely by expanding nursing homes. This is because many of the models did not show a tendency that higher nursing care abundance reduces the values of the factors which increase more hospital beds. This finding was particularly relevant in middle-density regionality groups. This finding suggests that the location of nursing homes should be monitored because of concerns about the oversupply of nursing homes and sprawl in those areas.

Correlation analysis between agronomic character and yield of Padjadjaran maize hybrids at medium and high population densities

Correlation analysis between agronomic character and yield of Padjadjaran maize hybrids at medium and high population densities

The influence of agro- and urbangenic fragmentation of the natural environment on the structure of Collembolan taxocenes of the Eastern Podillia

A comparative analysis of the taxonomic and ecological structure of Collembolan urbo- and agrotaxocenes of Eastern Podillia with their forest and meadow-steppe variants was carried out. Urbotaxocenes are represented by 39 species, and agrotaxocenes by 30 species of Collembola. A characteristic feature of the fragmented urbo- and agrotaxocenes of the studied region is the "xerophyllization" of the fauna (enrichment with drought-resistant species), the large mosaic distribution of the abundance of species in the soil, as well as the specificity and unpredictability of their taxonomic and ecological structure. The investigated collembolan taxocenes are characterized by low and medium population density (urbotaxocenes from 2.1 to 6.3 thousand individuals/m2 individuals/m2; agrotaxocenes from 0.2 to 0 .8 thousand inhabitants/m2). Under the influence of urban fragmentation of the natural environment, multidirectional and often unforeseeable restructuring of the ecological structure of the collembolan taxocenes has been recorded. In the spectrum of ecological groups, this influence causes an increase in the number of xeroresistant collembola and a decrease in hygrophilous ones. In the ratio of biotope groups of Collembola, there is an increase in the representation of meadow-steppe (on average more than 44%), eurytopic (25%) and forest-meadow (24%) forms due to a decrease in forest and meadow forms. That is why different types of collembolan taxocenes can form in urbo-soils - eurytopic or specialized. Under the influence of agrogenic fragmentation of the environment in the spectrum of ecological groups, an increase in the representation of meadow-steppe (on average more than 55%), forest-meadow (about 20%) and forest (over 14%) forms was recorded due to a decrease in eurytopic (about 9%) and grasslands (1%). That is why a specialized collembolan taxocene can form in agricultural soils.

Impact of nursing home characteristics on COVID-19 infections among residents and staff

Excess mortality occurred in nursing homes during the SARS-CoV pandemic. This study aimed to identify risk factors for COVID-19 infection and mortality in nursing home residents and staff in Hesse, Germany. A retrospective cohort study of 687 nursing homes was performed. We used t tests and logistic regressions to quantify the role of nursing homes' size, location, staff qualification, and room occupancy as potential risk factors. The bivariate statistics show that a higher proportion of infected staff and for-profit operations were associated with an increase in infections among residents and staff, while more single rooms and registered nurses showed protective effects. Our model calculations also show that the presence of a higher ratio of registered nurses was a significant protective factor against resident infection (odds ratios [OR]: 0.969, P=.002), resident mortality (OR: 0.973, P=.006), and safeguarded staff (OR: 0.979, P=.034). In contrast, more single rooms (OR: 0.993, P=.029) were protective for residents, while increased risk factors included more beds (OR: 1.006, P=.006 for residents' infections, OR: 1.008, P<.001 for mortality) and infected staff (OR: 2.363, P<.001 for residents' infections). For staff, medium population density (OR: 2.322, P=.016) and infected residents (OR: 1.308, P<.001) were associated with elevated risk. Preventing infection outbreaks among residents and staff is crucial to reduce mortality. Strategies include increasing single-occupancy rooms, improving staff qualifications, and targeting facilities with lower registered nurse ratios and single-occupancy rooms for inspection.

Modeling the impact of urban land cover features and changes on the land surface temperature (LST): The case of Jordan

Higher land surface temperature (LST) in cities than their surrounding areas presents a major sustainability challenge for cities. Decision-makers and planners use the LST measurements to monitor the urban environment to reduce the urban climate’s main challenges. Therefore, there is an urgent need to examine the impacts of urban features and changes on the LST. This study focused on the relationship between LST and urban land changes and the impact of these changes on LST during different periods. Although a set of studies explored the relationship between landscape features and urban LST, several aspects still need further discussion. Here, the study aims to explore the influence of landscape features and land cover patterns on land surface temperature LST in two cities (Amman and Zarqa) in Jordan, and identify which of these features (vegetation cover, built-up and population density) has the most effective and influence on LST values. Therefore, this paper is the first study about land surface temperature LST and its relations with these aspects in Jordan. This study used a mixed method approach using quantitative method (GIS) and qualitative method (comparative case studies). This study revealed that the most important features affecting the LST values were: (1) Population density; (2) Built-up; and (3) Vegetation, and in descending order from the strongest to the least effective. It is also concluded that in the city in which the population density is high, the effect of built-up areas on the values of LST is as high as possible and positive more than the cities with medium and low population density. As for the city in which the population density is medium to low, the effect of vegetation cover on the values of LST is greater, and this can be more positive than in cities with a high population density. Therefore, the study contributes to improving the planners' and policymakers’ suitable future decisions for making sustainable cities.

Domestic water quality and the discriminatory influence of socio-economic stratification on accessibility to safe water in a part of Osun State, Nigeria

The status of the water supplied to households in an urban local government area in southwest Nigeria was examined. Specific objectives were to characterize household water sources, assess the per capita usage of potable water sources and examine quality of the household water in the area. The purposively selected study area, Olorunda local government area in Osun State, Nigeria (being an urban local government area) was stratified into ‘urban core’ (central business district, CBD or high population density area), ‘transition’ (medium population density area but with less social infrastructure) and ‘sub-urban’ (typically government reserved area and low population density area) based on household density and associative socio-economic status. The methods were a mix of questionnaire administration to heads of 120 households (40 per stratum) and collection of the drinking water samples from the supply sources at four randomly selected households in each stratum. The water samples were analysed for the concentrations of nitrite (NO2-), nitrate (NO3-), fluoride (F-), lead (Pb) and arsenic (As) as well as E-coli bacteria contents based on their importance in determining water quality in urban areas. The results showed that domestic water sources are mainly hand dug well (55.8%), borehole (37.5%) and pipe borne (6.7%). Residents averagely consumed at most 4L of water per day. Furthermore, the investigated chemical parameters varied as NO2 (0.37-0.94 mg/l), NO3 (0.29-0.70 mg/l), and F- (0.003-0.97 mg/l). As and Pb occurred in trace quantities, and there were no pollution threats to consumers. The amount of E coli and total coliform contents were however outside the safe limits for residents, suggesting contamination of household water by the bacteria sources. The study concluded communities with low socio-economic status which do not have access to state-provided tap water source are more likely to consume polluted water than those with high socio-economic status or that are supplied with state-provided tap water. The study advocates improve urban water management for the urban fringe dwellers.

The relationship between urban greenness and mental health: A national-level study of China

The relationship between urban greenness and residents' mental health is a critical subject of academic research, but no conclusive findings have been identified yet. Based on a large-scale social survey dataset in China, this study explores the association between urban greenness and residents’ mental health and the moderating effect of the built and social environments on the association. The research found that urban greenness is significantly and positively associated with residents’ mental health, to varying degrees, in cities with different built and social environments. In cities with medium scale and population density, greenness is found to be more significantly associated with residents’ mental health, as it is in cities with a higher level of social fairness. The findings not only lend support to the health promotion model of social ecology, which suggests that mental health is associated with the external built and social environments, but also provides evidence to understand the benefits of urban greenness as a public good. In healthy city-oriented planning practices, multiple factors in the built and social environments should be considered in order to give full play to the health benefits of urban greenness.

Public exposure to broadband electromagnetic fields and its association with population density and building density: The case study of Beijing

The gradual increase in electromagnetic field (EMF) exposure levels poses a potential threat to human health and the normal operation of electronic systems. In order to know the environmental EMF conditions, measurements were carried out on roads of about 400 km in the urban area of Beijing, China. The measurement results show that the electric field strength of about 89% of the sampling points is within 3 V/m, and the electric field strength of other sampling points is relatively high. Combined with further spectrum analysis, it was found that the electric field strength of one road section exceeded the national standard limits. In addition, to help quickly identify the general condition of the environmental EMF, a set of procedures for mining the association rules between the electric field strength and population density and building density is proposed in this paper. The final association rules show that the electric field strength is usually lower than 1.5 V/m in areas with medium or lower population density and areas with low building density; the electric field strength in areas with extremely high population density and areas with high building density is usually 1.5-4 V/m; while the electric field strength higher than 4 V/m mainly occurs in areas with extremely high population density. It is recommended to focus on strengthening the monitoring of EMF in areas with extremely high population density, and at the same time continuously pay attention to the trend of the urban EMF levels, so as to achieve early warning and treatment of relevant risks.

Analysis of the Type and Distribution Features of Public Services Based on Civic Tech Concept

Owing to the development of Information Communication Technology (ICT) and the human and financial resources of public institutions, the task of improving public services is increasingly being transferred to the private sector. Civic Tech (CT), a form of public service delivery by ICT professionals in collaboration with citizens, is spreading from the United States to the world and creating many new public services. This study analyzes CT-based public services worldwide by clustering, dimension analysis, and co-occurrence analysis. This study concludes that CT-based public services are generally divided into two forms: direct service delivery to users, which fixes and replaces existing public services, and the creation of generic tools that indirectly support the improvement of public services. Moreover, the fact that the majority of CT-based public services are located in middleincome, medium-population density countries and regions can be a constraint on funding and talent that prevents CT organizations from generating or sustaining the public services created by CT organizations in areas where new and alternative public services are most needed.

Impact of test, vaccinate and remove protocol on home ranges and nightly movements of badgers in a medium density population

In the British Isles, the European badger (Meles meles) is thought to be the primary wildlife reservoir of bovine tuberculosis (bTB), an endemic disease in cattle. Test, vaccinate or remove (‘TVR’) of bTB test-positive badgers, has been suggested to be a potentially useful protocol to reduce bTB incidence in cattle. However, the practice of removing or culling badgers is controversial both for ethical reasons and because there is no consistent observed effect on bTB levels in cattle. While removing badgers reduces population density, it may also result in disruption of their social behaviour, increase their ranging, and lead to greater intra- and inter-species bTB transmission. This effect has been recorded in high badger density areas, such as in southwest England. However, little is known about how TVR affects the behaviour and movement of badgers within a medium density population, such as those that occur in Northern Ireland (NI), which the current study aimed to examine. During 2014–2017, badger ranging behaviours were examined prior to and during a TVR protocol in NI. Nightly distances travelled by 38 individuals were determined using Global Positioning System (GPS) measurements of animal tracks and GPS-enhanced dead-reckoned tracks. The latter was calculated using GPS, tri-axial accelerometer and tri-axial magnetometer data loggers attached to animals. Home range and core home range size were measured using 95% and 50% autocorrelated kernel density estimates, respectively, based on location fixes. TVR was not associated with measured increases in either distances travelled per night (mean = 3.31 ± 2.64 km) or home range size (95% mean = 1.56 ± 0.62 km2, 50% mean = 0.39 ± 0.62 km2) over the four years of study. However, following trapping, mean distances travelled per night increased by up to 44% eight days post capture. Findings differ from those observed in higher density badger populations in England, in which badger ranging increased following culling. Whilst we did not assess behaviours of individual badgers, possible reasons why no differences in home range size were observed include higher inherent ‘social fluidity’ in Irish populations whereby movements are less restricted by habitat saturation and/or that the numbers removed did not reach a threshold that might induce increases in ranging behaviour. Nevertheless, short-term behavioural disruption from trapping was observed, which led to significant increases in the movements of individual animals within their home range. Whether or not TVR may alter badger behaviours remains to be seen, but it would be better to utilise solutions such as oral vaccination of badgers and/or cattle as well as increased biosecurity to limit bTB transmission, which may be less likely to cause interference and thereby reduce the likelihood of bTB transmission.

Population Density Cluster Analysis in DKI Jakarta Province Using K-Means Algorithm

This study aims to analyze clusters based on the area and population density of the area and population density of the area in DKI Jakarta Province in 2015 using the data mining method by clustering as the first step in planning for population equality. The subject of analysis in this study is a village located in the province of DKI Jakarta which is recorded based on the area and population density in each sub-district until 2015 with several stages, namely data understanding, data processing or cleansing, cluster tendency assessment, clustering, cluster review. From this study, the results were obtained that the data tended to be clustered because the statistical value of Hopkins was close to the value of 0 and in VAT there was a vague picture of clusters that might be formed. Based on this, cluster creation is carried out using the K-Means Algorithm. Based on the results, there are 3 clusters formed, namely cluster 0 (not densely populated), cluster 1 (medium population density), and cluster 2 (densely populated). These results can be used as a basis for policy making in population management.

Heterogeneity in the Effect of Environmental Protection Expenditure in China: Causal Inference from Machine Learning

ABSTRACT The amount of fiscal expenditure on environmental governance in various regions of China in recent years has increased greatly, but its effect on environmental protection is often controversial in existing research. The conflicting finding is largely due to endogenous problems or selection bias. Generally, the cities with high smog pollution have been encountering environmental protection expenditure (EPE) shocks more greatly since 2011. To estimate the causal effects of EPE shocks more accurately, this research uses new machine learning to the estimate heterogeneous treatment effect of the EPE shock on urban air pollution from 216 cities in China, from 2011 to 2018. Empirical results from causal forests show the following. First, the positive EPE shock has contributed to China’s short-term improvements in air pollution. Long-term causality has not been confirmed statistically, though there is a strong correlation between an increase in EPE and a decrease in PM2.5. Second, a positive EPE shock leads to deterioration of smog in low-income and above-medium smog areas in the long term. Third, the positive EPE shock is conducive to the long-term improvement of air quality in moderately industrialized areas, but it does not lead to the long-term improvement of urban air pollution with a high or low degree of industrialization. Similarly, an EPE shock in cities with medium population density improves air quality for a long time, but runs the opposite in cities with high or low population density.

PERTUMBUHAN GULMA ALANG-ALANG (Imperata cylindrica L. Beauv.) PADA BERBAGAI KONDISI KEPADATAN SETELAH PEMOTONGAN DI PETROCHINA INTERNATIONAL JABUNG LTD.

This research aims to find out the growth of I. cylindricaweed after cutting at various density conditions so that it can be determined the interval of precise control mechanically in the pipeline PetroChina International Jabung Ltd. The research was conducted by making random sample plots in various conditions of I. cylindrica population density. There were three population densities of I. cylindricaobserved, namely dense,mediun and rare. The results showed that height, number of tillers and dry weight of I. cylindrica were higher in dense and medium population densities than rare population densities. There is a shift in the dominant weed species in each condition of population density after cutting. The community of vegetation before and after cuttingat dense population density was classified as homogeneous with C value of 78.05%, while at medium and rare population density it wasclassifiedas heterogeneous with C value of &lt; 75%.Keywords:Imperata cylindrica, growth of weed, population density, species shift

Analysis of Spatial Concentrations of Large-Truck Crashes Using Data Mining Methods

In recent years, the number of studies on crashes involving large-trucks has increased due to its importance to the economy and the higher chance of fatalities. However, none of the previous studies has given attention to the spatial concentrations of large-truck crashes. Moreover, the literature lacks exploration of granular level land use and urban design factors. The current study used the DBSCAN (Density-Based Spatial Clustering of Application with Noise) method to identify the spatial concentrations of crashes involving large-trucks. Additionally, the study explored housing, population, employment, and road network density attributes along with the crash characteristics, roadway attributes, location type, traffic conditions, driver’s action and behavior, and environmental factors. The association rule analysis was employed to discover the contributory factors that lead to no injury, non-severe and severe injuries at the spatial concentrations of crashes involving large-trucks. The findings indicated that the rear-end collisions involving drunk drivers often lead to severe injuries in large-truck crashes. Non-interstate roads, speed limit from 40 to 80 kilometers per hour, high road network density, medium and high population density are frequent conditions of non-severe injuries. Lastly, collisions between large-trucks and fixed objects, sideswipe same direction collisions, snowy roads, clear weather, medium road network and employment density are likely to facilitate no injury crashes involving large-trucks. Road traffic authorities can use these insights to reduce the frequency and severity of crashes involving large-trucks at their spatial concentrations.

Source identification and health risk assessments of heavy metals in indoor dusts of Ilorin, North central Nigeria.

Exposure to heavy metals (HMs) in indoor dusts is a serious public concern that is linked to a myriad of deleterious health outcomes. The objectives of this study are to estimate the contamination levels of HMs in indoor dusts of different residential areas in Ilorin, Nigeria; identify HMs sources in different residential areas; and evaluate human health risks of HMs in selected residential areas. Indoor dust sampling was conducted in ten randomly selected from low, medium and high population density residential areas of Ilorin, Nigeria. Ten HMs concentration levels, their health risk implication and the associated potential ecological risks were evaluated. The mean concentration levels measured for Fe, Pb, Zn, As, Co, Cr, Cu, Cd, Mn and Ni were 38.99, 5.74, 3.99, 0.08, 2.82, 2.13, 0.47, 0.60, 6.45 and 1.09mg/kg, respectively. Positive Matrix Factorization (PMF) model was applied to ascertain sources of HMs in sampled indoor dust. Percentage contribution from oil-based cooking (29.82%) and transportation (29.77%) represented the highest source to HM concentrations among the six factors identified. The results of the various pollution indices employed showed that Pb, Zn, As, Co, Cr, Cu, Mn and Ni contributed moderately to HMs concentration levels in the sampled dusts. Cd had highest potential ecological risk factor of between 160 and 320. The average values of Enrichment Factors (EFs) obtained aside from Fe used as the reference metal, ranged between 8.46 (As) and 2521.61(Cd). Health risk assessment results revealed that children are the most susceptible to the risks associated with HMs bound indoor dust than the adults. The percentage risk contributions of Hazard Quotient via ingestion route (HQing) in Hazard Index (HI) for non-cancer risk of indoor HMs were 93.17% and 69.87% in children and adults, respectively. Likewise, the percentage cancer risks contribution through ingestion pathway (CRing) were higher than cancer risks through inhalation and dermal pathways (CRinh and CRdermal), accounting for 99.84% and 97.04% of lifetime cancer risk in children and adults, respectively. The contamination level of Cd recorded is of great concern and signifies very strong contribution from anthropogenic sources. This study has further revealed the levels of HMs in typical African residential settings that could be used by relevant stakeholders and policy makers in developing lasting control measures. The online version contains supplementary material available at 10.1007/s40201-021-00778-8.

Population downscaling using high-resolution, temporally-rich U.S. property data

ABSTRACT Multi-temporal and spatially explicit population data are vital in many fields, such as demography, urban planning, disaster prevention,economics, and environmental modeling. Population data used in these studies are typically aggregated at census enumeration units, which are too coarse for many applications. Accurate population downscaling methods are needed to obtain population data at finer spatial resolutions. We use a novel settlement-related database, Built-Up Property Records (BUPR) from the Historical Settlement Data Compilation for the United States (HISDAC-US) to downscale population from census tracts to block groups. The BUPR dataset provides the number of built-up property records for each 250-m grid at 5-year temporal resolution from 1810 to 2015 for most contiguous United States (CONUS). The ability of BUPR to downscale population from census tracts to block groups for four states, representing a range of population densities, is evaluated here by comparing against other commonly-used ancillary datasets. The BUPR-based method outperforms all other methods in all but one state with highly-incomplete BUPR. A more detailed accuracy assessment is performed by dividing each state into low, medium, and high population density categories. The BUPR method produces more accurate downscaled population estimates for low and medium categories, though its performance deteriorates in the high density category due to its relatively coarse spatial resolution. BUPR-based dasymetric mapping is subsequently applied to the CONUS and found to generalize well beyond the four comparison states with high downscaling accuracy. The long-term record of the HISDAC-US dataset enables the potential construction of fine-grained population data back to 1810.