Impact of exposure to hazardous substances on occupational disease risk across industries

Inclusion criteria

The inclusion and exclusion criteria were established to ensure the selection of important studies. The current research included original research articles (cohort studies, case–control studies, cross-sectional studies, and randomized controlled trials) as well as narrative reviews published within the past 15 years. Studies that empirically assessed workplace exposure to hazardous substances and their connection to occupational diseases were also included.

The selected studies focused on specific hazardous substances commonly found in workplaces, such as heavy metals (lead, mercury, cadmium), chemical solvents (benzene, toluene, formaldehyde), dust and particulates (silica, asbestos), and industrial fumes and gases (carbon monoxide, ammonia, sulfur dioxide). In addition, the studies examined the direct link between exposure to these hazardous substances and the development of occupational diseases, including respiratory diseases, cancer, neurological disorders, and skin diseases.

The industries covered in the included studies focused on occupational settings such as manufacturing, construction, mining, and healthcare. Only peer-reviewed journal articles published between 2010 and 2025 were considered to ensure relevance. In addition, studies were included only if, for ease of access, they were published in English.

Exclusion criteria

Studies such as systematic reviews, meta-analyses, editorials, or theoretical papers without new empirical data were excluded. In addition, general environmental health studies that focus on toxic substances without workplace-specific exposure data were also excluded.

Furthermore, general environmental health studies that focus on toxic substances without workplace-specific exposure data, studies that only measure exposure levels without analyzing health effects or disease incidence, studies that focus on community exposures, studies older than 2010, and non-English studies were all excluded.

Manufacturing industry

Attarchi et al.^[6] from their cross-sectional study on the combined effect of cigarette smoking and occupational exposures on lung function, screened workers in the rubber industry, specifically tire manufacturing workers in production units, as they are more exposed to pulmonary health hazards. Their findings highlighted that workers exposed to both occupational hazards and cigarette smoke have significantly worse lung function compared to non-smokers or those with only one exposure; synergistic effects between cigarette smoking and workplace toxins may accelerate lung function decline. The workers also had a higher frequency of respiratory symptoms such as coughing, wheezing, breathlessness, and reduced pulmonary function tests. These findings further imply that exposure at work alone impacts lung health; however, smoking exacerbates the effects, leading to a higher risk of respiratory disease progression.

Subramaniam et al.^[4] conducted a narrative review on the textile industry encompassing various processes such as ginning, spinning, weaving, dyeing, and printing. They discovered that exposure to endotoxins and cotton dust causes respiratory problems in a sizable percentage of textile workers. They said that endotoxins and cotton dust exposure have been linked to quantifiable deteriorations in lung function, raising the risk of long-term respiratory conditions. Furthermore, workers exposed to high noise levels in textile factories are at an increased risk of developing hearing loss, and the physical demands of textile work, including repetitive tasks and poor ergonomic conditions, lead to a higher incidence of musculoskeletal disorders among workers.

Research conducted by Awodele et al.^[5] examined workers in the paint manufacturing industry whose jobs were mixing raw materials and paint production, packaging of manufactured paints, and loading of paints into vehicles for appropriate distribution and marketing. The findings show that a greater proportion of respondents do not utilize these devices. Specifically, 61.5% do not wear goggles, 74.75% do not wear safety boots, 66.75% do not wear dust masks, 61.5% do not wear aprons, and 85.8% do not wear hand gloves. In total, 90% of those surveyed reported having symptoms associated with exposure to hazards, whereas just 10% said they had no symptoms. The most commonly reported health consequence (33.75%) was headache. Other symptoms include itching (5.5%), skin irritation (8.75%), eye discomfort (6.25%), and chronic fatigue (10.5%). The average levels of heavy metals (μg/mL) in urine samples from both paint and non-paint workers. When comparing paint workers to non-paint workers, the results reveal statistically significant (P < 0.05) increases in urine concentrations of lead, cadmium, arsenic, and chromium.

Tounsadi et al.^[7] conducted a cross-sectional epidemiological study to evaluate the occupational risks related to otolaryngology, dermatitis, and ophthalmological symptoms among the textile employees in a textile factory. Their findings report that a significant number of workers reported experiencing symptoms related to otolaryngological, dermatological, and ophthalmological health issues, indicating a strong association between chemical exposure and these conditions. The study found a high correlation between the use of toxic chemicals, adverse working conditions, and the prevalence of reported health symptoms. The environmental evaluation verified that workers are exposed on a daily basis to dangerous and toxic chemicals, posing a substantial threat to their health.

Power and steel industries

Dehury and Kumar^[8] carried out a cross-sectional study aimed at identifying occupational morbidity and workplace injuries in the power and steel industries. Their findings stated that the majority of workers experienced injuries, musculoskeletal pain, and body pain. From the study population, additional occupational illnesses were found, including heat stroke, itching, fever, electric shock, vision and hearing issues, and respiratory conditions. The study discovered that among workers in the power and steel industries, occupational morbidity was correlated with demographic factors such as household income, occupation, and technical education.

Healthcare/industry

Rai et al.^[9] conducted a cross-sectional study to determine the frequency of exposures among Bhutanese HCPs to a variety of chemicals used in healthcare settings. According to their findings, the prevalence of exposure to one or more carcinogens, ototoxic agents, and asthmagens was 28.1%, 7.6%, and 98.7%, respectively; the prevalence for anesthetic gases and antineoplastic medications was 2.2% and 6.2%, respectively. The most frequent exposures were to formaldehyde in the carcinogens group, p-xylene among ototoxic agents, latex, and cleaning and disinfecting chemicals in the asthmagens group. Utilizing latex gloves, washing with bleach and chlorhexidine, utilizing formaldehyde as a disinfectant and in the laboratory, and using p-xylene in the laboratory were the situations that led to exposures.

In addition, Supapvanich et al.^[10] conducted a cross-sectional study to determine the prevalence of dermal and respiratory symptoms associated with latex glove use in nurses in Thailand and evaluate the influence of previously reported occupational risk factors in this population. According to their findings, 18% of the 899 nurses who participated in the study reported health consequences related to latex product use. After controlling for confounding, wearing more than 15 pairs of protective lead gloves per day (odds ratio (OR): 2.10, 95% confidence interval [CI]): [1.32–3.34]), using chlorhexidine (OR: 2.07, 95% CI: [1.22–3.52]), and working as an operating room nurse (OR: 2.46, 95% CI: [1.47–4.12]) were occupational risk factors linked to higher reporting of dermal symptoms. Only working as a labor ward nurse was linked to higher reporting of respiratory symptoms (OR: 3.52, 95% CI: [1.26–9.85]).

Furthermore, Arif and Delclos^[3] conducted a cross-sectional study in the healthcare industry, examining professionals routinely exposed to disinfectants and cleaning supplies at their workplace. We looked at the prevalence of occupational asthma (OA), Work-exacerbated asthma (WEA) and work-related asthma symptoms (WRAS), and none. The relative percentages of WRAS, WEA, and OA were 3.3%, 1.1%, and 0.8%, according to their findings. In general, female HCPs have greater prevalence estimates than male HCPs. For the longest work, exposure to cleaning chemicals and disinfectants/sterilants increased the risks of WRAS and WEA in a dose-dependent way. Both factor 1 (bleach, cleaners/abrasives, toilet cleaners, detergents, and ammonia) and factor 2 (glutaraldehyde/ortho-phthaldehyde, chloramines, and ethylene oxide) had significantly higher risks of WRAS for exposure in any employment. Exposure to bleach, factor 2, and formalin/formaldehyde was found to significantly increase the likelihood of developing WEA. Chloramine exposure was substantially linked to about 5 times the risk of developing OA.

Multi-industry analysis

Fukai et al.^[11] conducted a case–control study on various industries to examine whether the number of types of hazardous operations at work experienced through a lifetime is associated with cancer incidence, and additionally examined the combined effects with lifestyle-related factors. Their findings revealed that workers with experience in hazardous operations exhibited a higher incidence of cancers across all sites, notably in the bladder, pancreas, and lung. For all sites, the multivariable-adjusted ORs for cancer incidence were 1 (reference) and 1.16 (95% CI: 1.12–1.21) for one type of hazardous operation, and 1.17 (95% CI: 1.08–1.27) for two or more types, indicating a significant trend (P for trend <0.001). There were notable combined associations between hazardous operations and smoking, particularly elevating the risks for lung, pancreatic, and bladder cancers. A significant combined effect was observed between hazardous operations and diabetes, specifically increasing the risk of pancreatic cancer.

Furthermore, Anderson and Meade,^[12] from their narrative review on potential health effects associated with dermal exposure to occupational chemicals from different industries such as agriculture, manufacturing, cosmetology, health care, cleaning, painting, mechanics, printing/lithography, and construction found that factors such as extensive hand washing, frequent wet work, hand sanitizer use, exposure to chemical mixtures, or wearing occlusive gloves can change the integrity or function of the skin and play a role in enhancing chemical penetration or sensitization by influencing additional biological responses.