Analysis of Heavy Metals in some Processed Forms of Cannabis Sativa Commonly Consumed in Adamawa State, Nigeria

Abstract

This study assesses the concentrations of heavy metals in three major cannabis processed forms (Bush, Arizona, and Loud) sold in Adamawa State, Nigeria. Cannabis samples were systematically collected from three key locations—Numan, Mubi, and Yola—representing the state’s senatorial districts. The study employed standardized methodologies for sample pre-treatment, digestion, and analysis using atomic absorption spectrometry (AAS) to quantify seven heavy metals: cadmium (Cd), zinc (Zn), iron (Fe), chromium (Cr), manganese (Mn), lead (Pb), and copper (Cu). A rigorous digestion process was utilized, combining concentrated nitric acid and hydrochloric acid in optimal ratios to ensure comprehensive analysis. The findings revealed the absence of cadmium (Cd) and chromium (Cr) in all tested cannabis samples. Lead (Pb), however, was detected in the Bush and Arizona varieties obtained from Numan, with levels reaching 0.68 mg/kg—exceeding the regulatory limit of 0.5 mg/kg set by WHO. Iron (Fe) emerged as the predominant metal across all samples, presenting a mean concentration of 19.36 mg/kg, followed by copper (Cu) at 5.86 mg/kg, manganese (Mn) at 2.79 mg/kg, and zinc (Zn) at 1.68 mg/kg. Despite most metals adhering to permissible thresholds, the elevated levels of lead (Pb) and iron (Fe) raise significant health concerns. Lead contamination poses a severe risk of neurological, respiratory, and cardiovascular disorders through immune modulation and oxidative stress mechanisms, while excessive iron accumulation disrupts cellular functions, potentially leading to liver damage, metabolic acidosis, and organ failure. These findings underscore the health hazards associated with heavy metal contamination in cannabis varieties sold in Adamawa State. The research advocates for stringent regulatory measures, public health awareness campaigns, and continuous monitoring to mitigate the risks posed by cannabis consumption and ensure consumer safety.