[Distribution, Respiratory Exposure, and Traceability of Atmospheric Microplastics in Yichang City]

As an emerging environmental pollutant, microplastics have attracted much attention, but the sources and health hazards of atmospheric microplastics (AMPs) remain unclear. In order to explore the distribution characteristics, assess the risk of human respiratory exposure, and analyze the sources of AMPs in different functional areas of Yichang City, AMPs samples from 16 observation points were collected and analyzed, and the HYSPLIT model was used. The results showed that the main shapes of AMPs in Yichang City were fiber, fragment, and film, and six colors were observed including transparent, red, black, green, yellow, and purple. The smallest size was 10.42 μm, and the largest was 4761.42 μm. The deposition flux of AMPs was (4400±474) n·(m²·d)^-1. The types of APMs were polyester fiber (PET), acrylonitrile-butadiene-styrene copolymer (ABS), polyamide (PA), rubber (Rubber), polyethylene (PE), cellulose acetate (CA), and polyacrylonitrile (PAN). The order of the subsidence flux in each functional area was as follows:urban residential area>agricultural production area>landfill>chemical industrial park>town residential area. The human respiratory exposure risk assessment models showed that the daily intake of AMPs (EDI) for adults and children in urban residential areas was higher than in town residential areas. The atmospheric backward trajectory simulation showed that the AMPs in the districts and counties of Yichang City mainly came from the surrounding areas via short-distance transportation. This study provided basic data support for the research on AMPs in the middle reaches of the Yangtze River and was of great significance for the traceability and health risk research of AMPs pollution.

Estimating neural activity from visual areas using functionally defined EEG templates

Electroencephalography (EEG) is a common and inexpensive method to record neural activity in humans. However, it lacks spatial resolution making it difficult to determine which areas of the brain are responsible for the observed EEG response. Here we present a new easy-to-use method that relies on EEG topographical templates. Using MRI and fMRI scans of 50 participants, we simulated how the activity in each visual area appears on the scalp and averaged this signal to produce functionally defined EEG templates. Once created, these templates can be used to estimate how much each visual area contributes to the observed EEG activity. We tested this method on extensive simulations and on real data. The proposed procedure is as good as bespoke individual source localization methods, robust to a wide range of factors, and has several strengths. First, because it does not rely on individual brain scans, it is inexpensive and can be used on any EEG data set, past or present. Second, the results are readily interpretable in terms of functional brain regions and can be compared across neuroimaging techniques. Finally, this method is easy to understand, simple to use and expandable to other brain sources.

Risk Assessment and Implication of Human Exposure to Road Dust Heavy Metals in Jeddah, Saudi Arabia

Data dealing with the assessment of heavy metal pollution in road dusts in Jeddah, Saudi Arabia and its implication to human health risk of human exposure to heavy metals, are scarce. Road dusts were collected from five different functional areas (traffic areas (TA), parking areas (PA), residential areas (RA), mixed residential commercial areas (MCRA) and suburban areas (SA)) in Jeddah and one in a rural area (RUA) in Hada Al Sham. We aimed to measure the pollution levels of heavy metals and estimate their health risk of human exposure applying risk assessment models described by United States Environmental Protection Agency (USEPA). Using geo-accumulation index (Igeo), the pollution level of heavy metals in urban road dusts was in the following order Cd > As > Pb > Zn > Cu > Ni > Cr > V > Mn > Co > Fe. Urban road dust was found to be moderately to heavily contaminated with As, Pb and Zn, and heavily to extremely contaminated with Cd. Calculation of enrichment factor (EF) revealed that heavy metals in TA had the highest values compared to that of the other functional areas. Cd, As, Pb, Zn and Cu were severely enriched, while Mn, V, Co, Ni and Cr were moderately enriched. Fe was considered as a natural element and consequently excluded. The concentrations of heavy metals in road dusts of functional areas were in the following order: TA > PA > MCRA > SA > RA > RUA. The study revealed that both children and adults in all studied areas having health quotient (HQ) < 1 are at negligible non-carcinogenic risk. The only exception was for children exposed to As in TA. They had an ingestion health quotient (HQing) 1.18 and a health index (HI) 1.19. The most prominent exposure route was ingestion. The cancer risk for children and adults from exposure to Pb, Cd, Co, Ni, and Cr was found to be negligible (≤1 × 10-6).

[Sediment Characteristics of Sewer in Different Functional Areas of Kunming]

The problem of sediment deposition in urban sewer network in different levels, will not only reduce the sewer flow ability, but also release pollutants and generate secondary pollution. The impact of secondary pollution is more serious in the study area, Kunming, because of the combined sewer overflow in rainy season. In order to obtain the characteristics of the sewer sediments in Kunming, the sewer sediments from residential area, service area, cultural district, and business district were investigated and collected. The particle size, density, organic matter (VSS/TSS) and pollutant content of the sediments were analyzed in this study. The results showed that there were different characteristics for the sediments from different areas. The size of the sediments exhibited business district >cultural district >residential area >service area, and the D₅₀ was concentrated in the 20 to 100 μm except the business district. As for VSS/TSS, the order was residential area >cultural district >business district >service area. It was negatively correlated with the dry density with the correlation index of R²=0.9827 and positively correlated with the water content. The contents of sediments showed significant differences in different functional areas. The size of COD presented residential area >cultural district >service area >business district, and the size of TN followed residential area >cultural district >business district >service area. As for TP, it exhibited residential area >service area >cultural district >business district. The COD, TN and TP were proportional to the population density of the area and TP was greatly influenced by sediment particle size. From the branch into the Sub-main sewer, COD and TN were irregular, and TP decreased slightly. TP mainly existed as particulate and was more likely to deposit onto the small particle. As for TN, there was no obvious rule about its distribution in different particle size sections. The pollution load was generally on the high side in Kunming. The content of heavy metals in business district was the highest among all functional areas, and the concentrations of Cu, Zn, Pb, Cd were 284.6, 786.4, 201.2, 2.54 mg·kg^-1 respectively. The average contents of Cu, Zn, Pb, Cd in urban area were 2.2, 4.4, 2.5, 8.6 times than the background values. It is suggested to control Cd and Zn with priority.

Fine Particulate Matter Pollution and Hospital Admissions for Respiratory Diseases in Beijing, China

Fine particulate matter has become the premier air pollutant of Beijing in recent years, enormously impacting the environmental quality of the city and the health of the residents. Fine particles with aerodynamic diameters of 0~0.3 μm, 0.3~0.5 μm, and 0.5~1.0 μm, from the yeasr 2007 to 2012, were monitored, and the hospital data about respiratory diseases during the same period was gathered and calculated. Then the correlation between respiratory health and fine particles was studied by spatial analysis and grey correlation analysis. The results showed that the aerial fine particulate matter pollution was mainly distributed in the Zizhuyuan sub-district office. There was a certain association between respiratory health and fine particles. Outpatients with respiratory system disease in this study area were mostly located in the southeastern regions (Balizhuang sub-district office, Ganjiakou sub-district office, Wanshoulu sub-district office, and Yongdinglu sub-district office) and east-central regions (Zizhuyuan sub-district office and Shuangyushu sub-district office) of the study area. Correspondingly, PM₁ (particulate matter with aerodynamic diameter smaller than 1.0 um) concentrations in these regions were higher than those in any other regions. Grey correlation analysis results showed that the correlation degree of the fine particle concentration with the number of outpatients is high, and the smaller fine particles had more obvious effects on respiratory system disease than larger particles.