Assessment of Source of Contamination of Heavy Metals and Estimation of Metals Risk in Smokeless Tobacco Products

Estimations of potential risk of carcinogenic arsenic in smokeless tobacco products

“…To determine the As exposure through SLTs, we calculated the estimated daily intake (EDI) of As by multiplying SLT consumption rate (IR) with the corresponding As residues according to the following equation:where EDI is the estimated daily intake of As (μg day −1 ); IR is the ingestion rate for the selective smokeless tobacco products (g day −1 ), which is the average amount of SLTs consumed per day. 12…”

“…13 The reference dose (RfD o ) value for arsenic (As) is 0.0003 mg kg −1 day −1 . Target hazard quotients for metals were determined based on the following formula: 14 where ED is the exposure duration of 70 years; EF is the exposure frequency of 365 days per year; IR is the smokeless tobacco consumption rate taken from the literature; 12 C As is the amount of As in the SLT samples (Table 5). RfD o is the oral reference dose average lifetime (mg kg −1 day −1 ); BW is the average body weight (60 kg), and LE is the average exposure time in days (365 days per year × 70 years); 10 −3 is the conversion factor.…”

“…The exposure length (year) is denoted by ED; the exposure frequency (day) is denoted by EF; and body weight is represented by BW. LE stands for the exposed person's life expectancy in days; IR is the smokeless tobacco consumption rate taken from the literature; 12 C iAs is inorganic As, which was determined according to Copat et al by assuming 3% total concentration of As in the studied samples. 15 CSF is the cancer slope factor, and its value for iAs is 1.50 per mg kg −1 day −1 .…”

“…where EDI is the estimated daily intake of As (mg day À1 ); IR is the ingestion rate for the selective smokeless tobacco products (g day À1 ), which is the average amount of SLTs consumed per day. 12 2.4. Target hazard quotient (THQ)…”

“…The amount of SLTs consumed per day was based on the survey conducted by Rehman et al (2016). The average daily intake for As was calculated; 12 the data are listed in Table 5. There was a large variation in As intake among SLTs.…”