The findings of this study underscore the critical role that informal e-waste recycling activities at Agbogbloshie play in contributing to severe environmental pollution and associated health risks. Elevated levels of heavy metals, including cadmium, chromium, copper, lead, mercury, nickel, and zinc, were observed in both soil and ambient air samples. These concentrations significantly exceed permissible limits set by organizations such as the WHO and FAO, indicating a pressing need for regulatory intervention and improved waste management practices.
Impact on Environmental Health
The high levels of heavy metals detected at the dismantling and burning sites highlight the severe contamination resulting from informal recycling methods. For instance, cadmium concentrations in ambient air at the dismantling site ranged from 83.333 ng/m³ to 138.889 ng/m³ with a mean value of 112.847 ng/m³, while soil cadmium concentrations at the burning site ranged from 3.98 mg/kg to 5.30 mg/kg with a mean value of 4.74 mg/kg. Both measurements exceed the WHO limits for cadmium in ambient air (5.00 ng/m³) and soil (3.00 mg/kg) (Fig. 2, Fig. 3).
Chromium levels in ambient air were highest at the dismantling site, with concentrations ranging from 743.06 ng/m³ to 1173.61 ng/m³ and a mean value of 942.71 ng/m³. Soil chromium concentrations were also elevated, with the burning site showing the highest mean concentration (139.45 mg/kg), both surpassing the permissible limits (100.00 ng/m³ for air and 100.00 mg/kg for soil) (Fig. 4, Fig. 5).
Copper concentrations in air were highest at the burning site, ranging from 1173.61 ng/m³ to 2090.28 ng/m³ with a mean value of 1536.46 ng/m³. Soil samples from the dismantling site showed extremely high copper levels (10178.55 mg/kg), significantly above the permissible limit of 100.00 mg/kg (Fig. 6, Fig. 7).
Lead concentrations in ambient air were highest at the burning site, ranging from 750.00 ng/m³ to 2965.28 ng/m³ with a mean value of 1751.74 ng/m³, exceeding the WHO limit of 500.00 ng/m³. In soil, the burning site recorded the highest lead levels (2455.98 mg/kg), well above the WHO/FAO limit of 50.00 mg/kg (Fig. 8, Fig. 9).
Mercury levels in ambient air were highest at the dismantling site (6.01 ng/m³ to 13.51 ng/m³ with a mean value of 9.92 ng/m³), within OSHA limits. Soil mercury concentrations were highest at the dismantling site (2.47 mg/kg to 2.69 mg/kg with a mean value of 2.59 mg/kg), marginally above the permissible limit of 2.00 mg/kg (Fig. 10, Fig. 11).
Nickel concentrations in ambient air were highest at the burning site, ranging from 125.00 ng/m³ to 173.61 ng/m³ with a mean value of 156.25 ng/m³, exceeding the NAAQS limit of 20 ng/m³. Soil samples from the burning site recorded the highest nickel levels (71.18 mg/kg), surpassing the WHO/FAO limit of 50.00 mg/kg (Fig. 12, Fig. 13).
Zinc concentrations in both air and soil were elevated, with the dismantling site recording the highest soil zinc levels (10178.55 mg/kg), far above the permissible limits (Fig. 14, Fig. 15).
Human Health Implications
The elevated concentrations of heavy metals in ambient air and soil at Agbogbloshie pose significant health risks to the local population. Chronic exposure to these metals can lead to various health issues, including respiratory problems, cardiovascular diseases, and cancer. For example, the high levels of cadmium detected in the air and soil at the dismantling and burning sites can lead to kidney damage and osteoporosis (Azimi et al., 2006). Similarly, prolonged exposure to lead is known to cause severe neurological and cardiovascular issues (Khan et al., 2008). Lead concentrations in air at the burning site (1751.74 ng/m³) and in soil (2455.98 mg/kg) far exceed safe limits, highlighting the potential for significant health impacts. The study's findings are consistent with previous research indicating that informal e-waste recycling activities significantly contribute to environmental contamination and pose health risks to workers and nearby residents (Caravanos et al., 2011). The contamination levels at Agbogbloshie are comparable to other ewaste recycling sites globally, such as those in China and India, where similar health and environmental issues have been documented (Robinson, 2009; Abiodun et al., 2019).
Regulatory and Policy Recommendations
The results of this study underscore the urgent need for robust regulatory frameworks and effective waste management practices to mitigate the environmental and health impacts of e-waste recycling. Regulatory bodies must enforce stringent guidelines to control the release of hazardous substances during recycling processes. Implementing safe and sustainable recycling practices, such as the use of closed-loop systems and proper waste segregation, can significantly reduce the release of heavy metals into the environment (Caravanos et al., 2011).
Moreover, there is a need for comprehensive monitoring and assessment programs to regularly evaluate the levels of environmental contaminants at e-waste recycling sites. Such programs can help identify pollution hotspots and inform targeted interventions to mitigate contamination (Page, 1994).
Future Research Directions
Future research should focus on assessing the long-term health impacts of heavy metal exposure on the local population, particularly vulnerable groups such as children and pregnant women. Longitudinal studies can provide valuable insights into the chronic health effects of exposure to heavy metals from e-waste recycling activities. Additionally, research should explore the effectiveness of various remediation strategies to clean up contaminated sites and restore environmental quality (Asante et al., 2012).