Formaldehyde Exposure, Health Symptoms and Risk Assessment among Hospital Workers in Malaysia

Formaldehyde is a chemical commonly used in hospitals as a tissue preservative;histopathology laboratory personnel are therefore among the workers most heavily exposed to formaldehyde. This study measured the formaldehyde exposure through ambient and personal air sampling, assessed the symptoms of poor health as well as estimating the health risk among hospital workers. We conducted a comparative cross-sectional study of both histopathology laboratory (exposed) and administration (nonexposed) workers in four hospitals in the Klang Valley, Selangor, Malaysia. Ambient and personal exposure to formaldehyde was measured using the OSHA 52 and NIOSH 2541 methods, respectively. The 8-hr time-weighted-average formaldehyde concentration was higher in exposed areas (0.25 ± 0.11 ppm) than nonexposed areas (0.08 ± 0.02 ppm). Histopathology workers were exposed to between 140% and 480% higher concentrations of formaldehyde than administration workers. Personal exposure was highest during grossing tasks (0.797 ± 0.436 ppm). A total of 67% of the exposed workers exhibited the same ten health symptoms related to formaldehyde exposure, and 57% of the nonexposed workers reported similar symptoms at their current workplace. Notably, symptoms of eye irritation, headache, drowsiness, and chest tightness were significantly more prevalent (p < 0.05;chi square and Fisher’s exact tests) among the exposed workers than the nonexposed workers. Among those with symptoms, 37% of the exposed workers, and 16% of the nonexposed workers believed that the symptoms were related to their current working environment. The noncancer effect of formaldehyde from air inhalation poses a potential risk of eye irritation among exposed workers. The cancer risk was not significant in both groups. Formaldehyde levels and symptoms of poor health were significantly higher among the exposed group. Exposure and risk could be minimised by strengthening control measures to improve indoor air quality in the workplace.

Heavy Metal Levels and Risk Assessment from Consumption of Marine Fish in Peninsular Malaysia

Fish consumption is one of the primary sources of protein in Malaysia. However, harmful substances, including heavy metals released from anthropogenic sources may accumulate in marine organisms through the food chain. Hence, human health risks may occur through the consumption of fish contaminated by heavy metals. This study was conducted to determine the concentrations of heavy metals and to assess health risks in edible tissues of 296 commonly consumed marine fish throughout Peninsular Malaysia. The marine fish samples were collected from selected major fish landing ports throughout Peninsular Malaysia. This paper focused on nine heavy metals concentrations namely selenium (Se), cadmium (Cd), lead (Pb), copper (Cu), zinc (Zn), antimony (Sb), tin (Sn), chromium (Cr) and manganese (Mn) in 46 species of marine fish. The fish samples were digested using a microwave digestion system (Multiwave 3000, Anton Paar). Heavy metals concentrations were analyzed by Inductively Coupled Plasma Mass Spectrometry (ICP-MS) ELAN 9000 (Perkin Elmer, Sciex, Canada). The heavy metals concentrations in marine fish samples were found to be dominated by Zn followed by Sn, Se, Cu, Mn, Cr, Pb, Cd and Sb which ranged between 15.9612 mg/kg (Zn) and 0.0002 mg/kg (Sb) wet weight. Among the investigated fish species, Otolithoides biauritus demonstrated the lowest concentration for all heavy metal except for Pb. The estimated weekly intakes (EWI) for all samples in this study were below the established PTWI by JECFA of FAO/WHO. Risk assessment results showed that the hazard quotient (HQ) and hazard index (HI) values were lower than 1 in all fish species. The results indicate that exposure to the studied metals poses a low non-carcinogenic risk and considered safe for human consumption.