Purpose: This study assessed the public health risk associated with formalin exposure in fresh water fish in Southern Bangladesh.
Methods: Formalin concentrations (mg/kg) were determined (n=3) in tilapia, Indian major carp rui, Chinese carp, and a minor carp from the local market and in laboratory simulations (0.5, 1.0, 2.0, and 4.0% formalin solution for 5, 15, 30, and 60 min) with spectrophotometric and HPLC method. A food frequency questionnaire was used to collect fish consumption (kg/kgBW.day) data from 400 respondents. A probabilistic exposure assessment was conducted using @Risk®7.0 software.
Results: Fish treated with increasing concentrations of formalin and time showed increased trends of formalin acquisition, irrespective to fish species and analytical methods used (P<0.05). The questionnaire survey showed higher consumption of rui and tilapia than Chinese carp and minor carp. Under spectrophotometric analysis, formalin exposure with consumption of four different fish was lower than ADI (0.2 mg/kgBW.day) and TDI (0.15 mg/kgBW.day) value for both total population (400 respondents, both consumer and nonconsumers) and consumers. Maximum exposure of formalin (0.28 mg/kg BW.day) was for tilapia (consumers) determined by the HPLC method. MoE provides high priority (<10,000) for tilapia and rui at P99 under spectrophotometric analysis; whereas, under HPLC analysis, tilapia had much lower MoE values at P99, P95, and P90 (total population and consumers).
Significance: This study suggested that exposure to formalin associated with tilapia consumption is a public health concern in Southern Bangladesh. Thus, it is a priority for risk management strategies and should be taken into consideration.