Trends in elemental Pb concentrations within atmospheric PM2.5 and associated risk to human health in major cities of China.

High concentrations of elemental lead (Pb) in the atmosphere pose a serious threat to human health. This study presents and summarizes data obtained from relevant literature on Pb concentrations within fine particulate matter (PM2.5) recorded in major cities in China from 2008 to 2019. An environmental health risk assessment model was then used to evaluate the health hazards of inhaling Pb among adults and children in China. Owing to the promulgation and implementation of a series of air pollution control measures, the Pb concentrations within PM2.5 measured in major cities in China showed a downward trend after peaking in 2013. The concentrations were higher in winter than in summer, and higher in northern cities than in southern cities. Although the Pb concentrations in most cities did not exceed the limit (500 ng/m3) set by China, they remained much higher than concentrations recorded in developed countries. The results of the environmental health risk analysis showed that the non-carcinogenic risk from atmospheric Pb exposure was higher in children than in adults (adult females > adult males), while the carcinogenic risk was higher in adults than in children. This study shows that even if the health risk of Pb in PM2.5 does not exceed the acceptable limit, stricter Pb pollution control measures are required to safeguard population health due to the dangers of Pb.

Knowledge, Practice of Personal Hygiene, School Sanitation, and Risk Factors of Contracting Diarrhea among Rural Students from Five Western Provinces in China.

BACKGROUND: Diarrhea is a global public health issue and a leading cause of childhood malnutrition, growth disturbances, and mortality. The spread of diarrhea is closely linked to the knowledge and maintenance of personal hygiene and quality of drinking water and sanitation facilities. However, there are few such investigations and analysis in rural areas of China. This study aims to determine the association between the risk of contracting diarrhea and knowledge and practices of personal hygiene and school sanitation among rural students as well as provide a scientific basis for preventing the spread of diarrhea and other infectious diseases. A stratified cluster sampling method was used to randomly select 12 rural primary schools in each of 5 counties where the Water, Sanitation and Hygiene (WASH) Plus Program has been implemented. The counties are located in the Guangxi Zhuang autonomous region, Chongqing municipality, Guizhou province, Yunnan province, and Xinjiang Uygur autonomous region. A single fourth-grade class was randomly chosen from each of the 60 schools for observation and a questionnaire survey. The study involved a total of 2330 students. The logistic regression method was adopted to determine the factors contributing to diarrhea in rural students. The results show that male students accounted for 49.40% (n = 1151) of the 2330 research subjects; the average age of the students was 9.9 ± 0.3 years. Approximately 33.09% of the students suffered from diarrhea in the three months leading up to the survey. The odds ratios (ORs) of students who did not know that "diarrhea can be prevented by washing fruits before eating them raw and not drinking untreated water" (OR: 1.303, 95% confidence interval [CI]: 1.063, 1.597) and that "the disease can be prevented by washing hands before meals and after going to the toilet" (OR: 1.522, 95% CI: 1.207, 1.920) were higher than those who knew the above stated facts. Students who "have drunk untreated water at school" (OR: 1.584, 95% CI: 1.268, 1.978), "have drunk untreated water at home" (OR: 1.643, 95% CI: 1.319, 2.048), and "did not wash hands before every meal" (OR: 1.490, 95% CI: 1.120, 1.983) were at a higher risk of contracting diarrhea than those who drank treated water at school and at home and washed their hands before every meal. Diarrhea was more likely to affect students who attended schools with unclean and poorly maintained toilets (OR: 1.586, 95% CI: 1.261, 1.995) or toilets with flies (OR: 1.383, 95% CI: 1.114, 1.717) and without adequate drinking water facilities (OR: 1.407, 95% CI: 1.009, 1.962). The knowledge of methods to maintain personal hygiene, general hygiene practices, and school sanitation are the three major risk factors that account for the spread of diarrhea among rural students from five western provinces (municipalities and autonomous regions) of China. Therefore, to prevent such diseases and maintain health, it is important to provide students with health education, help them develop good hygiene habits, ensure the provision of clean water at schools, and improve the overall school environments.

The exposome in practice: an exploratory panel study of biomarkers of air pollutant exposure in Chinese people aged 60-69 years (China BAPE Study).

The exposome overhauls conventional environmental health impact research paradigms and provides a novel methodological framework that comprehensively addresses the complex, highly dynamic interplays of exogenous exposures, endogenous exposures, and modifiable factors in humans. Holistic assessments of the adverse health effects and systematic elucidation of the mechanisms underlying environmental exposures are major scientific challenges with widespread societal implications. However, to date, few studies have comprehensively and simultaneously measured airborne pollutant exposures and explored the associated biomarkers in susceptible healthy elderly subjects, potentially resulting in the suboptimal assessment and management of health risks. To demonstrate the exposome paradigm, we describe the rationale and design of a comprehensive biomarker and biomonitoring panel study to systematically explore the association between individual airborne exposure and adverse health outcomes. We used a combination of personal monitoring for airborne pollutants, extensive human biomonitoring, advanced omics analysis, confounding information, and statistical methods. We established an exploratory panel study of Biomarkers of Air Pollutant Exposure in Chinese people aged 60-69 years (China BAPE), which included 76 healthy residents from a representative community in Jinan City, Shandong Province. During the period between September 2018 and January 2019, we conducted prospective longitudinal monitoring with a 3-day assessment every month. This project: (1) leveraged advanced tools for personal airborne exposure monitoring (external exposures); (2) comprehensively characterized biological samples for exogenous and endogenous compounds (e.g., targeted and untargeted monitoring) and multi-omics scale measurements to explore potential biomarkers and putative toxicity pathways; and (3) systematically evaluated the relationships between personal exposure to air pollutants, and novel biomarkers of exposures and effects using exposome-wide association study approaches. These findings will contribute to our understanding of the mechanisms underlying the adverse health impacts of air pollution exposures and identify potential adverse clinical outcomes that can facilitate the development of effective prevention and targeted intervention techniques.

Exploring personal chemical exposures in China with wearable air pollutant monitors: A repeated-measure study in healthy older adults in Jinan, China.

The health impact of airborne contaminants has been challenging to assess due to current limitations in measurement technologies. The emergence of wearable passive samplers coupled with high resolution mass spectrometry (HR-MS) chemical analysis has enabled comprehensive characterization of personal exposures. We conducted a repeated-measure study among 84 older adults in Jinan, China, as part of the Biomarkers for Air Pollutants Exposure (China BAPE) study. Study objectives were: 1) to characterize the occurrence, magnitude, and distribution of personal exposure to airborne contaminants; 2) to evaluate the temporal variation of chemical exposures across the study population; and 3) to identify behavioral and environmental factors that influence the observed variance in chemical exposures. The FreshAir wristband was worn by participants for three consecutive days each month from September 2018 to January 2019 and collected with paired time-activity logs. Passive air samplers were also deployed in parallel at a local outdoor air monitoring station. Spearman's Rho trend test and trajectory cluster analysis were used to identify exposure trends and variation patterns, respectively. Out of the 70 airborne compounds of potential concern screened, 26 compounds from 10 chemical classes were found to be above detection thresholds across >70% of the study population. Personal exposures were predominantly characterized by nine polycyclic aromatic hydrocarbons (PAHs), four phthalates, three nitroaromatics, and two volatile organic compounds (VOCs). Phthalate personal exposures were positively correlated with outdoor temperatures while the inverse relationship was observed for certain PAHs (p < 0.05). Specifically, dimethyl phthalate (rs = 0.31) decreased as temperatures declined, while nitrobenzene (rs = -0.35) and naphthalene (rs = -0.40) increased as temperatures decreased. Compared to levels measured at the outdoor air monitoring site, personal exposure of phthalates was elevated (p < 0.05) and hexachlorobutadiene was lower across participants (p < 0.01). Personal exposure of these chemicals was further found to be weakly associated with daily duration participants spent outdoors. Individuals formed distinct clusters based on trajectories of chemical exposures across the sampling period (September to January), potentially suggestive of distinct emission sources. In conclusion, we demonstrate the feasibility of characterizing the occurrence and magnitude of personal exposure to airborne chemical contaminants using passive wristband samplers. The temporal variability of these personal exposure profiles was highlighted and with distinct trends identified across different groups of individuals. Future studies will integrate this data with other omics datasets collected from this population of Chinese older adults to investigate associations between exposure profiles and health relevant biomarkers, to provide evidence in feasibility of disease prevention through environmental improvements.

Risk factors and on-site simulation of environmental transmission of SARS-CoV-2 in the largest wholesale market of Beijing, China.

From June 11, 2020, a surge in new cases of coronavirus disease 2019 (COVID-19) in the largest wholesale market of Beijing, the Xinfadi Market, leading to a second wave of COVID-19 in Beijing, China. Understanding the transmission modes of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the personal behaviors and environmental factors contributing to viral transmission is of utmost important to curb COVID-19 rise. However, currently these are largely unknown in food markets. To this end, we completed field investigations and on-site simulations in areas with relatively high infection rates of COVID-19 at Xinfadi Market. We found that if goods were tainted or personnel in market was infected, normal transaction behaviors between sellers and customers, daily physiological activities, and marketing activities could lead to viral contamination and spread to the surroundings via fomite, droplet or aerosol routes. Environmental factors such as low temperature and high humidity, poor ventilation, and insufficient hygiene facilities and disinfection practices may contribute to viral transmission in Xinfadi Market. In addition, precautionary control strategies were also proposed to effectively reduce the clustering cases of COVID-19 in large-scale wholesale markets.

Exploring the external exposome using wearable passive samplers - The China BAPE study.

Environmental exposures are one of the greatest threats to human health, yet we lack tools to answer simple questions about our exposures: what are our personal exposure profiles and how do they change overtime (external exposome), how toxic are these chemicals, and what are the sources of these exposures? To capture variation in personal exposures to airborne chemicals in the gas and particulate phases and identify exposures which pose the greatest health risk, wearable exposure monitors can be deployed. In this study, we deployed passive air sampler wristbands with 84 healthy participants (aged 60-69 years) as part of the Biomarkers for Air Pollutants Exposure (China BAPE) study. Participants wore the wristband samplers for 3 days each month for five consecutive months. Passive samplers were analyzed using a novel gas chromatography high resolution mass spectrometry data-processing workflow to overcome the bottleneck of processing large datasets and improve confidence in the resulting identified features. The toxicity of chemicals observed frequently in personal exposures were predicted to identify exposures of potential concern via inhalation route or other routes of airborne contaminant exposure. Three exposures were highlighted based on elevated toxicity: dichlorvos from insecticides (mosquito/malaria control), naphthalene partly from mothballs, and 183 polyaromatic hydrocarbons from multiple sources. Other exposures explored in this study are linked to diet and personal care products, cigarette smoke, sunscreen, and antimicrobial soaps. We highlight the potential for this workflow employing wearable passive samplers for prioritizing chemicals of concern at both the community and individual level, and characterizing sources of exposures for follow up interventions.

High-Pressure Homogenization Pre-Treatment Improved Functional Properties of Oyster Protein Isolate Hydrolysates.

The effects of HPH (high-pressure homogenization) pre-treatment on the functional properties of OPIH (oyster protein isolates hydrolysates) were studied. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis profiles, solubility, particle size distribution, zeta potential, surface hydrophobicity, emulsifying activity index and microstructure of emulsions were analyzed. Results indicated that HPH pre-treatment increased the accessibility of OPI to trypsin hydrolysis, resulting in decease in particle size, increase in solubility, absolute zeta potential, surface hydrophobicity and emulsifying activity index. In addition, HPH pre-treated OPIH emulsions became more uniform and the particle size of droplets decreased. These results revealed that HPH pre-treatment has the potential to modify the functional properties of OPIH.

Effects of high-pressure homogenization on functional properties and structure of mussel (Mytilus edulis) myofibrillar proteins.

Mussel myofibrillar proteins (MMP) suspensions (10.6% ±â€¯0.5%, w/v) were treated by high-pressure homogenization (HPH) at 0 (control), 20, 40, 60, 80 or 100 MPa for 3 cycles. Particle size distribution, zeta potential, solubility, water and oil holding capacity, emulsifying, foaming properties, secondary structure, free sulfhydryl and surface hydrophobicity of the obtained suspensions were analyzed. The results showed that functional properties of MMP significantly (P < 0.05) improved after HPH treatment. Absolute zeta potential, emulsifying activity index, emulsion stability index, foaming ability and foaming stability increased by 23.64 mV, 14.99 m2/g, 4.3 min, 17.3% and 29.7% at 80 MPa, protein solubility and oil holding capacity increased by 7.4% and 1300% at 100 MPa. However, HPH treatment significantly (P < 0.05) decreased particle size and water holding capacity. HPH treatment altered secondary structure, tertiary and quaternary structure. Functionality improvements mainly resulted from changes in structure and decrease in particle size. The results showed that HPH has potential for improving functional properties of MMP, thus expand its application in food industry.

Effects of Limited Hydrolysis and High-Pressure Homogenization on Functional Properties of Oyster Protein Isolates.

In this study, the effects of limited hydrolysis and/or high-pressure homogenization (HPH) treatment in acid conditions on the functional properties of oyster protein isolates (OPI) were studied. Protein solubility, surface hydrophobicity, particle size distribution, zeta potential, foaming, and emulsifying properties were evaluated. The results showed that acid treatment led to the dissociation and unfolding of OPI. Subsequent treatment such as limited proteolysis, HPH, and their combination remarkably improved the functional properties of OPI. Acid treatment produced flexible aggregates, as well as reduced particle size and solubility. On the contrary, limited hydrolysis increased the solubility of OPI. Furthermore, HPH enhanced the effectiveness of the above treatments. The emulsifying and foaming properties of acid- or hydrolysis-treated OPI significantly improved. In conclusion, a combination of acid treatment, limited proteolysis, and HPH improved the functional properties of OPI. The improvements in the functional properties of OPI could potentiate the use of oyster protein and its hydrolysates in the food industry.

Molecular cloning and functional characterization of cathepsin D from sea cucumber Apostichopus japonicus.

Cathepsin D (CTSD, EC 3.4.23.5) belongs to aspartic protease family, which is located in lysosomes and is distributed in diverse tissues and cells. CTSD has a wide variety of physiological functions, owing to its proteolytic activity in degradating proteins and peptides. In the current study, the full length cDNA of sea cucumber (Apostichopus japonicus) cathepsin D (AjCTSD) was firstly cloned, then the association between AjCTSD and sea cucumber autolysis was investigated. The full length cDNA of AjCTSD was 2896 bp, with an open reading frame (ORF) for 391 amino acids. AjCTSD was widely expressed in body wall, muscle and intestine; the expression level was the highest in intestine, followed by muscle and body wall. Compared to fresh tissues, AjCTSD expression levels were significantly increased in all examined autolytic tissues. The purified recombinant AjCTSD promoted the degradation of sea cucumber muscle. In conclusion, AjCTSD contributed to sea cucumber muscle autolysis.

Characterization of proteolysis in muscle tissues of sea cucumber Stichopus japonicus.

The proteolysis in muscle tissues of sea cucumber Stichopus japonicus (sjMTs) was characterized. The proteins from sjMTs were primarily myosin heavy chains (MHCs), paramyosin (Pm), and actin (Ac) having a molecular mass of approximately 200, 98, and 42 kDa, respectively. Based on SDS-PAGE analysis and quantification of trichloroacetic acid (TCA)-soluble peptides released, degradation of muscle proteins from sjMTs was favorable at pH 5 and 50°C. Proteolysis of MHCs was mostly inhibited by cysteine protease inhibitors, including trans-epoxysuccinyl-L-leucyl-amido (4-guanidino) butane (E-64) and antipain (AP). E-64 and AP completely inhibited the degradation of Pm and Ac, while iodoacetic acid showed a partially inhibitory effect. These results indicated that the proteolysis of sjMTs was mainly attributed to cysteine proteases. Avoidance of setting the tissues at 40-50°C and slightly acidic condition and inhibition of cysteine proteases are helpful for decreasing sea cucumber autolysis.