Fuzzy based risk assessment of abattoir operations and treatment facilities: A case study of Onitsha North/South Lga of Anambra State of Nigeria

•Risk is assessment of abattoirs is necessary for bio-economy development.•The development of criteria for abattoir risk assessment is essential.•Fuzzification and integration of operational, facility and locational risks.•It is demonstrate using a case study of five abattoirs.•The overall fuzzy-based risk assessment ranged from moderate to severe risk. Increasing risk exposures emanating from slaughterhouses in developing countries calls for urgent attention, Risk Assessment (RA) was applied to five abattoirs using fuzzy logic system in Anambra State of Nigeria. Previous research works on abattoir operations asserted their risk assessment on subjective basis and descriptive statistics. The fuzzy based RA was therefore adopted because of its adeptness to incorporate operational, facility and locational risks. The risk evaluation criteria was developed by contributions from environmental experts in ministries, literatures and prepared by the authors. The evaluation criteria includes environmental risk with four sub-sections, personnel risk with two sub-sections and social risk with four sub-sections making it a total of 10 risks. Fuzzy Logic Toolbox in MATLAB software was used in the fuzzification and defuzzification process to obtain a 10 scale overall risk level ranging from 1 signifying ‘No Risk’ to 10 indicating “Very Strong/High risk”. The result of the study shows that the overall risk values of the abattoirs are 7.48, 5.05, 7.12, 6.83 and 7.48 for Ugwunabamkpa, Main Market, Marine, Ochanja and Bridge Head Abattoirs respectively. The overall fuzzy-based RA for the study location ranged from moderate to severe risk and is therefore proposed as appropriate tool for abattoir RA based on experts’ opinion and literatures from this study. It is therefore recommended that suitable equipment; personnel periodical training; improved meat plant sanitation; building adequate structures and good methods of abattoir effluent treatment with emphasis on biogas digestion should be employed as well as a thorough abattoir location analysis for risk reduction in the abattoirs.