Biomonitoring of metals in the blood and urine of waste recyclers from exposure to airborne fine particulate matter (PM2.5)

This is the first systematic investigation of occupational exposure to toxic metals among waste recyclers in municipal waste recycling facilities. Concentrations of heavy metals (HMs) in the blood and urine of exposed recyclers in different jobs were compared to control groups (administrative department), identifying possible work-related and socio-demographic exposure factors. The potential relationship between HMs levels in PM_2.5 and HM concentrations in the blood and urine of recyclers was studied for ten elements. Mean concentrations of HMs of recyclers were significantly higher than for the control group. Over 50% of the waste recyclers had HM levels higher than the recommended limits. The study revealed that most of the waste recyclers engaged in a minimum of three tasks, posing a challenge in establishing a correlation between specific tasks and the levels of elements monitored through biomonitoring. Co levels in blood and Fe levels in the urine of waste recyclers have a significant relationship with the increase in daily working hours. Among the variables related to the participant’s demographic information, the level of education and monthly income were significantly different compared to the control group. Also, a significant correlation was found between HM levels in PM_2.5 personal exposure and recyclers’ urine and blood. Management controls include workflow or, in other words, alternate relocation of workers exposed to severe risks. Engineering controls such as ventilation systems, applying appropriate personal protective equipment (PPE), and risk management methods are the implementation cases to reduce exposure.

Graphical abstract