Biochemical and reproductive biomarker analysis to study the consequences of heavy metal burden on health profile of male brick kiln workers

Abstract

The present study aims to assess the effect of a heavy metal burden on general health, biochemical parameters, an antioxidant enzyme, and reproductive hormone parameters in adult male brick kiln workers from Pakistan. The study participants (n = 546) provided demographic data including general health as well as body mass index. Blood was collected to quantitatively assess hematological, biochemical, and reproductive hormone parameters as well as heavy metal concentrations using both atomic absorption spectroscopy (AAS) and particle-induced X-ray emission (PIXE). The data showed that 10% of the brick kiln workers were underweight and 10% obese (P = 0.059), with workers also reporting multiple health issues. Heavy metal concentrations utilizing AAS revealed significantly (p = 0.000) higher levels of cadmium, chromium, and nickel, while PIXE detected more than permissible levels of Si, P, S, Cl, K, Ca, Zn, Ti (p = 0.052), Mn (p = 0.017), Fe (p = 0.055), Co (p = 0.011), Ni (p = 0.045), and Cu (p = 0.003), in the blood of kiln workers. Moreover, a significant increase in platelet count (P = 0.010), a decrease in sodium dismutase levels (p = 0.006), a major increase in reactive oxygen species (p = 0.001), and a reduction in protein content (p = 0.013) were evident. A significant increase in cortisol levels (p = 0.000) among the workers group was also observed. The concentration of LH and FSH increased significantly (p = 0.000), while that of testosterone decreased (p = 0.000) in the worker group compared with controls. A significant inverse relationship was found between cortisol, LH (r = − 0.380), and FSH (r = − 0.946), while a positive correlation between cortisol and testosterone was also evident (r = 0.164). The study concludes that increased heavy metal burden in the blood of brick kiln workers exposes them to the development of general and reproductive health problems due to compromised antioxidant enzyme levels, increased oxidative stress conditions, and a disturbing reproductive axis.

Mediation Effect of Body Mass Index on the Association of Urinary Nickel Exposure with Serum Lipid Profiles

“…An occupational study also revealed that Ni-exposed workers had a lower BMI than controls (23.20 ± 0.63 in workers vs. 24.63 ± 0.76 in controls) [ 22 ]. Besides, another study demonstrated that compared with non-workers, brick kiln workers had higher Ni levels but lower rate of overweight and obesity (29.4% in workers vs. 73.0% in non-workers) [ 21 ]. Our study also found a negative correlation between U-Ni and BMI, consistent with these previous studies.…”

“…However, it remains largely unclear whether Ni exposure influences human lipid levels. Moreover, several studies have revealed that Ni exposure may be associated with lower body weight or body mass index (BMI) [ 21 – 24 ], and BMI, as a surrogate indicator of body weight and obesity, is recognized to be closely related to lipid profiles and dyslipidemia. However, whether BMI plays a mediating role in this relationship remains unknown.…”

Brick kiln pollution and its impact on health: A systematic review and meta-analysis

“…Fifty-eight (56%) reported data on brick kiln pollution, 6,8,15-67 25 (24%) on health, 5, and 21 (20%) on both pollution and health. 7,9,[93][94][95][96][97][98][99][100][101][102][103][104][105][106][107][108][109][110] We mapped countries where brick kiln research was conducted in Figure 2. Most were in South Asia (Online Supplement).…”

“…79,90 Reproductive health risks Three studies reported data on reproductive health in BKWs. 9,73,101 One study conducted in Pakistan compared health risks in 232 female BKWs to 113 controls and found a lower age at menarche for BKWs when compared to controls (11.1 ± 0.16 years vs. 14.1 ± 0.19 years, respectively). 73 Female BKWs had a higher average number of pregnancies, abortions and stillbirths when compared to controls; however, controls were younger and fewer were married than BKWs.…”

“…Bricks are primarily fired using coal or biomass, but other fuels such as rubber tires, motor oils, trash and plastic are also common. [6][7][8][9] Throughout the brick making processes, workers are exposed to various airborne pollutants. Clay and brick dust contains high concentrations of silica, while the smoke emitted during brick firing contains particulate matter (PM) and gaseous pollutants including sulfur dioxide (SO2), carbon monoxide (CO), and nitrogen oxides (NOx).…”