Monitoring, Human Health Risk Assessment and Optimized Management for Typical Pollutants in Indoor Air from Random Families of University Staff, Wuhan City, China

Health risk assessment from inhalation exposure to indoor formaldehyde: A systematic review and meta-analysis

This systematic review and meta-analysis investigated studies on formaldehyde (FA) inhalation exposure in indoor environments and related carcinogenic (CR) and non-carcinogenic (HQ) risk. Studies were obtained from Scopus, PubMed, Web of Science, Medline, and Embase databases without time limitation until November 21, 2023. Studies not meeting the criteria of Population, Exposure, Comparator, and Outcomes (PECO) were excluded. The 45 articles included belonged to the 5 types of sites: dwelling environments, educational centers, kindergartens, vehicle cabins, and other indoor environments. A meta-analysis determined the average effect size (ES) between indoor FA concentrations, CR, and HQ values in each type of indoor environment. FA concentrations ranged from 0.01 to 1620 μg/m3. The highest FA concentrations were stated in water pipe cafés and the lowest in residential environments. In more than 90% of the studies uncertain (1.00 ×10-6 1.00 ×10-4) due to FA inhalation exposure was reported and non-carcinogenic risk was stated acceptable. The meta-analysis revealed the highest CR values due to inhalation of indoor FA in high-income countries. As 90% of the time is spent indoors, it is crucial to adopt effective strategies to reduce FA concentrations, especially in kindergartens and schools, with regular monitoring of indoor air quality.

Inhalational exposure to formaldehyde, carcinogenic, and non-carcinogenic risk assessment: A systematic review

Formaldehyde is one of the most widely used substances in a variety of industries, although it was classified as a human carcinogen by the International Agency for Research on Cancer (IARC). The present systematic review was conducted to retrieve studies related to occupational exposure to formaldehyde until November 2, 2022. Aims of the study were to identify workplaces exposed to formaldehyde, to investigate the formaldehyde concentrations in various occupations and to evaluate carcinogenic and non-carcinogenic risks caused by respiratory exposure to this chemical among workers. A systematic search was done in Scopus, PubMed and Web of Science databases to find the studies done in this field. In this review, studies that did not meet the criteria specified by Population, Exposure, Comparator, and Outcomes (PECO) approach were excluded. In addition, the inclusion of studies dealing with the biological monitoring of FA in the body and review studies, conference articles, books, and letters to the editors were avoided. The quality of the selected studies was also evaluated using the Joanna Briggs Institute (JBI) checklist for analytic-cross-sectional studies. Finally, 828 studies were found, and after the investigations, 35 articles were included in this study. The results revealed that the highest formaldehyde concentrations were observed in waterpipe cafes (1,620,000 μg/m³) and anatomy and pathology laboratories (4237.5 μg/m³). Carcinogenic and non-carcinogenic risk indicated the potential health effects for employees due to respiratory exposure as acceptable levels of CR = 1.00 × 10^-4 and HQ = 1, respectively were reported to be exceeded in more than 71% and 28.57% of the investigated studies. Therefore, according to the confirmation of formaldehyde's adverse health effects, it is necessary to adopt targeted strategies to reduce or eliminate exposure to this compound from the occupational usage.

Prediction of the Hypertension Risk of the Elderly in Built Environments Based on the LSTM Deep Learning and Bayesian Fitting Method

Hypertension has become the greatest risk factor for death in elderly populations. As factors influencing cardiovascular disease, indoor environmental parameters pose potential risks for older adults. In this study, elderly residents in Dalian (Liaoning Province, China) urban dwellings were selected as the research subjects, and the environmental parameters of the dwellings’ main activity rooms and the blood pressure parameters of the older adults were measured. Based on the Long Short-Term Memory (LSTM) deep learning algorithm and Bayesian fitting method, a hypertension disease model was established using the long-term environmental parameters to predict the hypertension risk of older adults in their building’s environment. The results showed that temperature, humidity, and some air quality parameters had an impact on blood pressure under single environmental factor, and the comprehensive environmental risks of high systolic blood pressure, high diastolic blood pressure, and high blood pressure were 16.44%, 0%, and 16.44% for the male elderly and 14.11%, 7.14%, and 17.55% for the female elderly, respectively. By comparing the results for the blood pressure measurement and prediction, it can be observed that the risk error of hypertension obtained by the algorithm maintains the variables’ relationship, and the result of the algorithm is reliable in this period. This technology can provide a basis for measuring environmental parameters and will be conducive to the development of an ecological smart building environment.

An Industrial Scale Synthesis of Adipicdihydrazide (ADH)/Polyacrylate Hybrid with Excellent Formaldehyde Degradation Performance

A simple and versatile route for industrial scale synthesis of adipicdihydrazide (ADH)/polymer hybrids with excellent performance of formaldehyde degradation is proposed in this paper. The ADH compound is uniformly dispersed in poly(methyl methacrylate-butyl acrylate-methacrylic acid) (P(MMA-BA-MAA)) latex, which is validated by UV and dispersibility tests. The results illustrate that ADH has excellent compatibility and dispersion stability without affecting the film formation of the polymer latex. Furthermore, scanning electron microscope (SEM) and mapping analysis of the hybrid films also demonstrate that ADH is homogenously dispersed in the polymer matrix. Compared with neat polymers, the thermal properties of hybrid films are improved, for example, T_0.5 increases by 8.3 °C. According to qualitative tests of the 4-amino-3-hydrazino-5-mercapto-1,2,4-triazol-red/green/blue (AHMT-RGB) method, the hybrid films demonstrate high formaldehyde removal efficiency. On the basis of the semi-quantitative test of Fourier Transform infrared spectroscopy (FTIR) measurements, the rate of formaldehyde degradation can reach 1.034 × 10² mol/(h·m³) for the hybrid film with 5 wt% ADH.

Do Urban Subway Openings Reduce PM2.5 Concentrations? Evidence from China

With the fast-growing consumption of automobiles in China, vehicle fumes appear to be one of the major contributors to PM2.5 (fine particles with a diameter of 2.5 μm or less) emissions. As a type of green transportation, Chinese urban subway transit has developed rapidly in recent years. This paper estimates the effect of urban subway openings on PM2.5 concentrations in Chinese cities. Using daily air quality data for 29 Chinese cities from 2013 to 2018, and using regression discontinuity design, we find that new subway openings reduce PM2.5 concentrations by an average of 18 μg/m3. The potential mechanism for this emission reduction is due to the offset in on-road transportation, and the use of cleaner energy. Also, central heating in winter, population scale, and city tier play crucial roles in the emission-reducing effect of subway openings. A series of robustness tests are conducted to support the fundamental empirical results. Targeted policy implications, such as optimizing the planning of urban subway construction and road network, fostering awareness of green travel, and promoting the innovation of emission-reducing technologies, are suggested for sustainable development in Chinese cities.

The Approach of Including TVOCs Concentration in the Indoor Environmental Quality Model (IEQ)—Case Studies of BREEAM Certified Office Buildings

The article analyzes the impact of measured concentrations of Total Volatile Organic Compounds (TVOC) emissions determined for four BREEAM certified buildings on the Indoor Air Quality Index (IAQindex) and the overall Indoor Environment Quality index (IEQindex). The IEQindex indicates the percentage of building users who are satisfied from the indoor environment. In existing IEQ models, currently the concentration of CO2 is mostly used to evaluate the IAQindex sub-component. Authors point out that it is recommended to use TVOC instead CO2 at pre-occupant stage where building is mainly polluted by emission from finishing products. The research provides the approach where the component related to the emission of TVOCs is implemented to IEQ model. The first stage of assessment was a test of the volatile organic compounds concentrations in case study buildings. Secondly, the analysis results were assigned into the number of dissatisfied users (PD(IAQ)) from the theoretical function given by Jokl-Fanger resulting from the Weber-Fechner equation. Finally, the overall IEQindex was calculated. The IEQ approach proposed in this paper is mainly based on a consideration of EN 15251 and scientifically accepted models.

Spatial Distribution and Fuzzy Health Risk Assessment of Trace Elements in Surface Water from Honghu Lake

Previous studies revealed that Honghu Lake was polluted by trace elements due to anthropogenic activities. This study investigated the spatial distribution of trace elements in Honghu Lake, and identified the major pollutants and control areas based on the fuzzy health risk assessment at screening level. The mean total content of trace elements in surface water decreased in the order of Zn (18.04 μg/L) > Pb (3.42 μg/L) > Cu (3.09 μg/L) > Cr (1.63 μg/L) > As (0.99 μg/L) > Cd (0.14 μg/L), within limits of Drinking Water Guidelines. The results of fuzzy health risk assessment indicated that there was no obvious non-carcinogenic risk to human health, while carcinogenic risk was observed in descending order of As > Cr > Cd > Pb. As was regarded to have the highest carcinogenic risk among selected trace elements because it generally accounted for 64% of integrated carcinogenic risk. Potential carcinogenic risk of trace elements in each sampling site was approximately at medium risk level (10^-5 to 10^-4). The areas in the south (S4, S13, and S16) and northeast (S8, S18, and S19) of Honghu Lake were regarded as the risk priority control areas. However, the corresponding maximum memberships of integrated carcinogenic risk in S1, S3, S10-S13, S15, and S18 were of relatively low credibility (50-60%), and may mislead the decision-makers in identifying the risk priority areas. Results of fuzzy assessment presented the subordinate grade and corresponding reliability of risk, and provided more full-scale results for decision-makers, which made up for the deficiency of certainty assessment to a certain extent.