Hazard Characterization and Health Risk Assessment of Locally Distilled Alcoholic Beverages in Southern Nigeria

Abstract

The consumption of locally distilled alcoholic beverages is widespread across Southern Nigeria; however, production often occurs under poorly regulated conditions, raising serious chemical, occupational, and public health concerns. This study undertook a comprehensive hazard characterization and health risk assessment of locally distilled alcoholic beverages in Lagos, Cross River, and Rivers States. Fifteen distillers, representing small-, medium-, and large-scale operations, were purposively selected for the study. Data were collected using structured questionnaires administered to distillers, Key Informant Interviews (KIIs) with local health officials and consumers, and laboratory analyses of beverage samples to determine concentrations of ethanol, methanol, fuel oils, acetaldehyde, and lead. Descriptive statistics were used to summarize production characteristics and chemical composition, while inferential analyses, including Pearson’s correlation and a one-sample t-test, were applied to assess health risks. Findings revealed wide variations in production scale, hygiene standards, and workforce size, with daily output ranging from 130 to 2,500 litres. Ethanol concentrations ranged between 35 and 42 per cent, while methanol levels varied from 0.3 to 0.7 per cent, occasionally exceeding recommended safety limits. Fuel oils, acetaldehyde, and lead were consistently detected across samples, particularly in medium- and large-scale operations. Health risk assessment identified moderate to high potential risks for consumers, with commonly reported symptoms including dizziness, nausea, blurred vision, and fatigue. To further test health risk significance, a one-sample t-test compared the mean estimated daily methanol intake (7.16 mg/day ± 3.45) against a conservative safety threshold of 5 mg/day. The results showed a statistically significant difference (t = 2.43, df = 14, p = 0.029), leading to rejection of the null hypothesis and confirming that methanol exposure from these beverages poses a significant health risk. Key Informant Interviews corroborated that unsafe production practices and risky consumption behaviours jointly contribute to exposure. The study concludes that locally distilled alcoholic beverages in Southern Nigeria present significant chemical and health hazards, underscoring the need for strengthened regulatory oversight, improved capacity building for distillers, and targeted public health awareness campaigns