Occupational Exposure and Health Impairments of Formaldehyde on Employees of a Wood Industry

Occupational health risk assessment of airborne formaldehyde in medical laboratories

The professional use of formaldehyde is a major occupational health concern in medical laboratory operations. Quantification of various risks associated with chronic exposure to formaldehyde may help in understanding the related hazards. This study designed to assess the health risks associated with inhalation exposure to formaldehyde involving biological, cancer, and non-cancer risks in medical laboratories. This study was performed in the hospital laboratories at Semnan Medical Sciences University. Risk assessment was performed in pathology, bacteriology, hematology, biochemistry, and serology laboratories with 30 employees, using formaldehyde in their daily routine operations. We determined area and personal exposures to airborne contaminant, applied standard air sampling, and analytical method recommended by National Institute of Occupational Safety and Health (NIOSH). We addressed formaldehyde-specific hazard by estimating peak blood level, life cancer risk, and the hazard quotient of non-cancer risks, adapted from Environmental Protection Agency (EPA) assessment method. The airborne formaldehyde concentrations in the laboratory personal samples ranged 0.0156-0.5940 ppm (mean = 0.195 ppm, SD = 0.048) and area exposure ranged 0.0285-1.0810 ppm (mean = 0.462 ppm, SD = 0.087). Based on workplace exposure, peak blood levels of formaldehyde were estimated at minimum 0.0026 mg/l to maximum 0.152 mg/l (mean = 0.015 mg/l, SD = 0.016). The mean cancer risk levels in terms of area and personal exposures were estimated respectively at 3.93 E - 8 μg/m³ and 1.84 E - 4 μg/m³, and for the non-cancer risk levels of the same exposures measured respectively at 0.03 μg/m³ and 0.07 μg/m³. Formaldehyde levels were significantly higher among laboratory employees, especially bacteriology workers. Exposure and risk could be minimized by strengthening control measures including the use of management controls, engineering controls, and respiratory protection equipment to reduce exposure levels of all workers to less than the allowed exposure limits and improve indoor air quality in the workplace.

Formaldehyde and Acetaldehyde Exposure in "Non-Traditional" Occupational Sectors: Bakeries and Pastry Producers

INTRODUCTION

Formaldehyde, a colorless and highly irritating substance, causes cancer of the nasopharynx and leukemia. Furthermore, it is one of the environmental mutagens to which humans are most abundantly exposed. Acetaldehyde was recently classified as carcinogen class 1B and mutagen class 2 in Annex VI EC regulation. Occupational exposure to the two aldehydes occurs in a wide variety of occupations and industries. The aim of this study is to deepen exposure to the two aldehydes in the non-traditional productive sectors of bakeries and pastry producers.

METHODS

The evaluation of exposure to formaldehyde and acetaldehyde was conducted in Italy in 2019, in specific tasks and positions of 11 bakeries and pastry producers (115 measures, of which 57.4% were in fixed positions and the rest were personal air sampling). The measurements were performed using Radiello© radial diffusion samplers. A logarithmic transformation of the data was performed, and the correlation between the two substances was calculated. Moreover, linear models considering the log-formaldehyde as the outcome and adjusting for log-acetaldehyde values were used.

RESULTS

The study identified high levels of acetaldehyde and formaldehyde exposure in the monitored workplaces. Higher mean values were observed in the leavening phase (8.39 µg/m³ and 3.39 µg/m³ for log-transformed data acetaldehyde and formaldehyde, respectively). The adjusted univariate analyses show statistically significant factors for formaldehyde as the presence of yeast, the presence of type 1 flour, the use of barley, the use of fats, the type of production, the use of spelt, and the presence of type 0 flour.

CONCLUSIONS

The measurements confirmed the release of formaldehyde and acetaldehyde in bakeries and pastry industries, especially in some phases of the work process, such as leavening.

Development of a Portable and Modular Gas Generator: Application to Formaldehyde Analysis

This work aims at developing and validating under laboratory-controlled conditions a gas mixture generation device designed for easy on-site or laboratory calibration of analytical instruments dedicated to air monitoring, such as analysers or sensors. This portable device, which has been validated for formaldehyde, is compact and is based on the diffusion of liquid formaldehyde through a short microporous interface with an air stream to reach non-Henry equilibrium gas–liquid dynamics. The geometry of the temperature-controlled assembly has been optimised to allow easy change of the aqueous solution, keeping the microporous tube straight. The formaldehyde generator has been coupled to an on-line formaldehyde analyser to monitor the gas concentration generated as a function of the liquid formaldehyde concentration, the temperature, the air gas flow rate, and the microporous tube length. Our experimental results show that the generated gaseous formaldehyde concentration increase linearly between 10 and 1740 µg m−3 with that of the aqueous solution ranging between 0 and 200 mg L−1 for all the gas flow rates studied, namely 25, 50 and 100 mL min−1. The generated gas phase concentration also increases with increasing temperature according to Henry’s law and with increasing the gas–liquid contact time either by reducing the gas flow rate from 100 to 25 mL min−1 or increasing the microporous tube length from 3.5 to 14 cm. Finally, the performances of this modular formaldehyde generator are compared and discussed with those reported in the scientific literature or commercialised by manufacturers. The technique developed here is the only one allowing to operate with a low flow rate such as 25 to 100 mL min−1 while generating a wide range of concentrations (10–1000 µg m−3) with very good accuracy.

Formaldehyde reinforces pro-inflammatory responses of macrophages through induction of glycolysis

Formaldehyde (FA) is widely used in chemical industry, which is also known as a common indoor air pollutant. Exposure of FA has been associated with multiple detrimental health effects. Our previous study showed that FA could inhibit the development of T lymphocytes in mice, leading to impaired immune functions. Macrophages are important innate immune cells which trigger inflammatory responses in tissues. In the present study, FA exposure at 2.0 mg/m³ was found to enhance the pro-inflammatory responses of macrophages in male BALB/c mice, which was confirmed by elevated pro-inflammatory cytokine release and NO secretion in macrophages isolated from the FA-exposed mice and in vitro macrophage models upon lipopolysaccharide stimulation. Glycolysis is the key metabolic process for the classical activation of macrophages, which was found to be elevated in the in vitro macrophage models treated with FA at 50 and 100 μM concentrations for 18 h. HIF-1α and the associated proteins in its signaling cascade, which are known to mediate glycolytic metabolism and inflammatory responses, were found to be upregulated by 50 and 100 μM FA in THP-1 derived and RAW264.7 macrophage models, and the enhanced pro-inflammatory responses induced by 100 μM FA were reversed by inhibitory compounds interfering with glucose metabolism or suppressing HIF-1α activity. Collectively, the results in this study revealed that FA could enhance the pro-inflammatory responses of macrophages through the induction of glycolysis, which outlined the FA-triggered metabolic and functional alterations in immune cells.

Health disorders and safety measures among workers in Tanta Flax and Oil Company, Egypt

Flax industry has an adverse effect on health status of exposed workers especially in developing countries with lack of appropriate safety measures to identify the health hazards, health disorders among workers in flax and oil company, and to assess the applied safety measures in the factory. A cross sectional study was conducted in Tanta Flax and Oil Company in Egypt. The company includes eight factories which are divided into four departments according to the manufacturing end products. The study was conducted from August 2018 to December 2019 on 353 workers out of 400 workers. An interview questionnaire and clinical medical examination were done to assess the health status of exposed workers. Check list from occupational safety and health administration (OSHA) standards was filled by researcher to check safety measures in work place environment. Respiratory manifestations were detected in 65% of the examined workers in flax manufacturing departments while allergic manifestations were more obvious in formaldehyde factory department. Approximately one quarter of workers complained that personal protective equipment's are not available. Regarding the mask for dust, nearly half (44.5%) of the workers rarely used them, and only 7.1% always use them. Byssinosis was obvious among workers in flax manufacturing and particle board manufacturing department with statistically significant differences between the four departments, in which 36.9% and 24.1% of workers in these two departments suffered from chest tightness, respectively. The safety measures were inadequate in flax manufacturing departments and to somewhat sufficient in formaldehyde factory department. Most of exposed workers had inadequate health status due to lack of standard safety measures. Therefore, periodic medical examination should be done regularly with investigation of pulmonary functions of exposed workers with application of high level of safety measure standards in the work place environment.

Simple click chemistry-based derivatization to quantify endogenous formaldehyde in milk using ultra-high-performance liquid chromatography/tandem mass spectrometry in selected reaction monitoring mode

RATIONALE

Formaldehyde (FA) exposure via environmental pollution or through the food chain poses a serious threat to human health, especially in developing countries like India. Although the addition of FA to food is proscribed, it is often illegally added to foods such as milk to increase the shelf-life. There are challenges in differentiating the endogenous FA content in milk from externally added FA.

METHOD

We have developed a simple method using ultra-high-performance liquid chromatography/tandem mass spectrometry in selected reaction monitoring mode (UHPLC/MS/SRM) for the absolute quantification of endogenous FA in milk. The steps include fat removal, protein precipitation using acid, and spiking with labelled FA (FA*), followed by simple click chemistry-based derivatization using Girard P reagent (GP) and final analysis.

RESULTS

A standard curve with FA* was constructed and used for the calculation of endogenous FA in milk. The optimal conditions for the derivatization reaction using 500 μL of milk were: GP, 50 μg; temperature, 37°C; time, 60 min; and 0.1% HCl. The validation parameters such as accuracy (95.84 to 99.73%), precision (2.84 to 8.02%) and spiked recovery (>95%) are within the FDA guidelines. This method is highly sensitive [limit of detection (LOD) of 1 ng/mL] with a dynamic range of 3.12 to 200 ng/mL. The endogenous FA level in pasteurized cow milk is 70 ng/mL (n = 60). The FA content in raw milk samples from cow, goat and buffalo (each n = 10) varied from 134 to 255 ng/mL.

CONCLUSIONS

This method is precise and sufficiently sensitive to quantify endogenous FA in milk samples using a minimal sample volume. As it involves simple sample preparation steps, it can be used routinely to quantify endogenous FA.

Knowledge, attitude and practice related to chemical hazards and personal protective equipment among particleboard workers in Ethiopia: a cross-sectional study

BACKGROUND

Work in the wood industry is often associated with exposure to wood dust and formaldehyde. The aims of this study were to describe the Knowledge, Attitude and Practice (KAP) concerning chemical health hazards among particleboard workers and to compare the KAP among temporary and permanent workers.

METHODS

A cross-sectional study design was used to collect data by structured questionnaires in two particleboard factories in Ethiopia. A total of 159 workers and 13 management personnel participated in this study. Both closed-ended and open-ended questions were included in the interviews. Chi-square tests, T tests and correlation analyses were used for categorical and continuous data. Total knowledge score (range 0-8) was calculated as the sum score of 8 items weighing one point each. Multiple linear regression was applied to estimate the impact of employment status on total knowledge score adjusted for level of education. Content analysis was applied to analyse collected data from open-ended questions.

RESULTS

The mean age of the respondents was 28 (SD = 6) years and on average they had 3.7 [3] years of service. The permanent workers were older than the temporary workers (29 vs 26 years, p = 0.001), and a considerably high fraction of the permanent workers had vocational education (90%) compared to the temporary workers (11%). Permanent workers had higher proportion of response on knowledge of 10 of 12 topics regarding chemical hazards and attitudes on 6 of 11 of these topics than temporary workers. Permanent workers had higher knowledge scores (3.7) compared to temporary workers (1.3) (p < 0.001), also after adjusting for education (p = 0.011). Permanent workers were provided with personal protective equipment (PPE) while temporary workers were not. The qualitative data helps to understand the workers and administrative personnel attitude and thinking regarding chemical hazards and PPE.

CONCLUSIONS

The findings revealed that permanent workers have higher proportion of positive response on knowledge and attitude towards chemical health hazards than temporary workers. However, practice in use of PPE depended on access to PPE. Few temporary workers were provided with PPE.

Respiratory Effects of Simultaneous Exposure to Respirable Crystalline Silica Dust, Formaldehyde, and Triethylamine of a Group of Foundry Workers

Background: Foundry workers are occupationally exposed to hazardous substances such as silica dusts and toxic gases. The aim of this study was to examine the effects of simultaneous exposure to complex mixtures of silica dust, formaldehyde, and triethylamine on lung function parameters.

Study design: A cross-sectional study.

Methods: This study was conducted on 55 male workers of core making unit of a foundry plant (the case group) and 55 workers in a food industry were enrolled as a control group in 2015. Workers were monitored for personal exposure to crystalline silica respirable dust, according the NIOSH method No.7602. The concentrations of formaldehyde and triethylamine were measured using a PID instrument. Lung function tests were performed according to the ERS/ATS standards.

Results: The mean concentrations of personal exposure to silica dust, formaldehyde, and triethylamine in the core making workers were 0.23 mg/m³ , 2.85 ppm, and 5.55 ppm and respective exposures of control subjects were less than the LOD (limit of detection). There were significant associations between exposure to silica dust and decreases in FVC (Forced vital capacity) values (P<0.05). The findings showed a statistically significant synergistic effect of silica dust and triethylamine on FVC values (P<0.05).

Conclusions: The mean exposure of all studied substances was higher than occupational exposure limits. Synergistic effects of exposure to silica dust and triethylamine on some lung function parameters were observed. Simultaneous exposure of foundry workers to silica dust and triethylamine could impair lung function.