Sample collection
Different parts of the chicken (liver, stomach, brest, small thigh, long thigh), feed (Rice polish, cannola meal, poultry biproducts, Broiler grower, Soybean, maiz, vitamin and mineral, L- threonine, L- lysine) were collected from Peshawar (P), Mardan (M), Nowshera (N), and Charsadda (C) in KPK. Then the sample were stored in polythene bags and kept in a refrigerator at -18℃.
Reagents used
All the chemicals used during the analysis were of analytical grade and purchased from Sigma Aldrich and Fisher chemicals. The chemicals used are concentrated nitric acid (HNO3 65%), and perchloric acid (HClO4 60%).
Sample Preparation
1.5g of each sample was digested in a mixture of HNO3 and HClO4 (3:1). The samples were heated in a digestion block heater for 1 hour at 95°C until a clear solution was obtained. The clear sample solution was diluted to 100 mL and filtered through Whatmann filter paper. The samples were stored in polyethylene bottles.
Intrumental conditions
A Hitachi z-2000 equipped with flame/graphite furnace with a hollow cathode lamp was used for all the analysis. The instrument is provided with a graphite auto sampler and Polarized Zeeman Background correction.
Estimated Daily Intake (Edi)
The EDI for arsenic was calculated using the following formula
$$\text{E}\text{D}\text{I}= \frac{\text{F}\text{I}\text{R} \times \text{C}}{\text{B}\text{W}}$$
where FIR is the ingestion rate of food (g/person/day), C is the arsenic concentration in food samples (mg/kg), and BW is the body weight [12, 15, 16].
Target Hazard Quotient (Thq)
THQ was used to calculate the non carcinogenic effect of As. Equation used
$$\text{T}\text{H}\text{Q}= \frac{{M}_{c}\times \text{C}\text{f}\times \text{I}\text{R}\times \text{E}\text{F}\times \text{E}\text{D}}{\text{R}\text{f}\text{D}\times \text{B}\text{W}\times \text{A}\text{T}} \times {10}^{-3}$$
THQ is the target hazard quotient, EFr is the frequency of exposure (365 days/year), ED represent the duration of exposure (70 years), FIR is the ingestion rate of food (g/person/day), C is the arsenic concentration in food (mg/Kg), RfD is the oral reference dose (mg/Kg/day), and AT is the average time for non carcinogens. The RfD for As is 3.0×10− 4 [12, 15, 16].
Target Cancer Risk (Tcr)
Target cancer risk was used to evaluate the carcinogenic risk of arsenic for the chicken users in Pakistan.
$$\text{T}\text{R}= \frac{\text{E}\text{F}\times \text{E}\text{D}\times \text{F}\text{I}\text{R}\times \text{C}\text{M}\times \text{C}\text{P}{\text{S}}_{\text{o}} }{\text{W}\text{A}\text{B}\times \text{A}{\text{T}}_{\text{c}}} \times {10}^{-3}$$
\(\text{E}\text{F}\) is the frequency of exposure to arsenic (365 days/), ED is the exposure duration (30 years)where TR is the target cancer risk, CM is the concentration of arsenic in chicken meat (µg/g), FIR is the ingestion rate of the chicken meat (g/day), CPSo is the carcinogenic potency slope, oral (mg/kg bw/day), and ATc is the averaging time, carcinogens (365 days/year for 70 year as used by USEPA 2011 [20]. The CPSo value for arsenic is 1.5 mg/kg body weight/day) [12].