Quantitative Health Risk Assessment of the Chronic Inhalation of Chemical Compounds in Healthcare and Elderly Care Facilities

Human exposure to formaldehyde and health risk assessment: a 46-year systematic literature review

After confirming that formaldehyde (FA) is carcinogenic, many studies were conducted in different countries to investigate this finding. Therefore, according to the dispersion of related studies, a bibliometric review of the current literature was performed with the aim of better understanding the exposure to FA and the resulting health risk, for the first time, using the Scopus database and the two open-source software packages, Bibliometrix R package. After screening the documents in Excel, the data was analyzed based on three aspects including performance analysis, conceptual structure, and intellectual structure, and the results were presented in tables and diagrams. A total of 468 documents were analyzed over period 1977-2023, in which 1956 authors from 56 countries participated. The number of scientific publications has grown significantly from 1977 (n = 1) to 2022 (n = 19). Zhang Y., from the Yale School of Public Health (USA), was identified as the most impactful author in this field. The Science of the Total Environment journal was identified as the main source of articles related to exposure to formaldehyde by publishing 25 studies. The United States and China were the most active countries with the most international collaboration. The main topics investigated during these 46 years included "formaldehyde" and "health risk assessment", which have taken new directions in recent years with the emergence of the keyword "asthma". The present study provides a comprehensive view of the growth and evolution of studies related to formaldehyde and the resulting health risks, which can provide a better understanding of existing research gaps and new and emerging issues.

Investigating the effectiveness of a new indoor ventilation model in reducing the spread of disease: A case of sports centres amid the COVID-19 pandemic

The ventilation of buildings is crucial to ensure indoor health, especially when demanding physical activities are carried out indoors, and the pandemic has highlighted the need to develop new management methods to ensure adequate ventilation. In Spain, there are no specific ventilation regulations to prevent the spread of pathogens such as the coronavirus. Therefore, it is necessary to have a theoretical tool for calculating occupancy to maintain sports facilities in optimal safety conditions. The proposed theoretical method is based on the analysis of mathematical expressions from European standardisation documents and uses the concentration of CO2 as a bioeffluent. It is also based on the concept of background and critical concentration, which allows its application to be extrapolated to future crises caused by pathogens. This study presents a unique and novel dataset for sports centres. For this purpose, the calculation methods were applied to the data set provided by Mostoles City Council, Spain, during the pandemic years with the highest incidence of COVID-19, when the government introduced the assimilation of COVID-19 sick leave to occupational accidents. The data on this type of sick leave provided by the City Council correspond to the period between March 2020 and February 2022. Similarly, the data on the average use of sports facilities by activity, provided by the Sports Department, correspond to the years 2020 and 2021. In this way, it was possible to verify the effectiveness in preventing the spread of any type of coronavirus. In conclusion, the implementation of a theoretical occupancy calculation method based on the concentration of carbon dioxide as a bioeffluent can be an effective tool for the management of future crises caused by pathogens or hazardous chemicals in the air, and demonstrated its effectiveness in sports centres such as gyms, sports fields, and indoor swimming pools during the COVID-19 pandemic.

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.

Health risk assessment of the European inhabitants exposed to contaminated ambient particulate matter by potentially toxic elements

PM₁₀-associated potential toxic elements (PTEs) can enter the respiratory system and cause health problems. In the current study, the health risk indices caused by PM₁₀ inhalation by adults, children, and infants in 158 European cities between 2013 and 2019 were studied to determine if Europeans were adversely affected by carcinogenic and non-carcinogenic factors or not. The Mann-Kendall trend test examined PM₁₀'s increasing or decreasing trend. Random Forest analysis was also used to analyse meteorological factors affecting PM₁₀ in Europe. Hazard quotient and cancer risk were estimated using PM₁₀-associated PTEs. Our results showed a decline in continental PM₁₀ concentrations. The correlation between PM₁₀ concentrations and temperature (-0.40), PBLH (-0.39), and precipitation were statistically strong (-0.21). The estimated Pearson correlation coefficients showed a statistically strong positive correlation between As & Pb, As & Cd, and Cd & Pb during 2013-2019, indicating a similar origin. PTEs with hazard quotients below one, regardless of subpopulation type, posed no noncancerous risk to Europeans. The hazard quotient values positively correlated with time, possibly due to elevated PTE levels. In our study on carcinogen pollution in Europe between 2013 and 2019, we found unacceptable levels of As, Cd, Ni, and Pb among adults, children, and infants. Carcinogenic risk rates were highest for children, followed by infants, adult women, and adult men. Therefore, besides monitoring and mitigating PM concentrations, effective control of PM sources is also needed.

Trihalomethane Cancer Risk Assessment for Private and Shared Residences: Addressing the Differences in Inhalation Exposure

The multi-pathway cancer risk (CR) assessment of trihalomethanes (THM) involves considering exposure via ingestion, dermal contact, and inhalation. Inhalation occurs during showering due to the volatilization of THMs from chlorinated water to the air. When assessing inhalation risks, exposure models commonly assume that the initial THM concentration in the shower room is zero. However, this assumption is only valid in private shower rooms where single or infrequent showering events take place. It fails to account for continuous or successive showering events in shared showering facilities. To address this issue, we incorporated the accumulation of THM in the shower room air. We studied a community (population ≈ 20,000) comprising two types of residences with the same water supply: population A with private shower rooms, and population B with communal shower stalls. The total THM concentration in the water was 30.22 ± 14.45 µg L^-1. For population A, the total CR was 58.5 × 10^-6, including an inhalation risk of 1.11 × 10^-6. However, for population B, the accumulation of THM in the shower stall air resulted in increased inhalation risk. By the tenth showering event, the inhalation risk was 2.2 × 10^-6, and the equivalent total CR was 59.64 × 10^-6. We found that the CR significantly increased with increasing shower duration. Nevertheless, introducing a ventilation rate of 5 L s^-1 in the shower stall reduced the inhalation CR from 1.2 × 10^-6 to 7.9 × 10^-7.

Early-Life Exposure to Formaldehyde through Clothing

Clothes contain a wide range of chemicals, some of them potentially hazardous. Recently, there has been a growing interest in eco-friendly clothing, including the use of organic cotton. However, the process of eco-friendly fabric production does not exclude the use of toxic substances, such as formaldehyde, a known human carcinogen. The present investigation was aimed at determining the presence of formaldehyde in eco-friendly and conventional clothing of pregnant women, babies, and toddlers from the Catalan (Spain) market. The potential effects of washing were also investigated by comparing the reduction of formaldehyde in unwashed and washed clothing. Formaldehyde was detected in 20% of samples, with a mean level of 8.96 mg/kg. Formaldehyde levels were surprisingly higher in eco-friendly than in regular garments (10.4 vs. 8.23 mg/kg). However, these differences were only significant (p < 0.05) for bras (11.6 vs. 7.46 mg/kg) and panties (27.1 vs. 6.38 mg/kg) of pregnant women. Dermal exposure and health risks were assessed for three vulnerable population groups: pregnant women, babies, and toddlers. In general, exposure was higher in babies (up to 1.11 × 10−3 mg/kg/day) than in other groups (2.58 × 10−4 and 4.50 × 10−3 mg/kg/day in pregnant women and toddlers, respectively). However, both non-carcinogenic and carcinogenic risks were below the safety limits (<1 and <10−5, respectively) according to national regulations. Notwithstanding, although formaldehyde levels were below the legal limits (<75 mg/kg) and health risks were within acceptable ranges, clothing may contain other toxic substances in addition to formaldehyde, thus increasing the risks. Finally, since no formaldehyde was detected in washed textile samples, a safe and simple practice for the consumers is to wash clothing before the first use.