agricultural land in Africa and Asia lies in climatic regions favorable for A. flavus and A. parasiticus proliferation. Suboptimal field practices and poor drying/storage condi- tions make crops vulnerable to fungal infec- tion and aflatoxin accumulation. Maize and groundnuts, the two crops most conducive to Aspergillus infection, are staples in many African and Asian diets. Because the very poor in these regions cannot afford much food vari- ety, these staples make up a significant portion of their diets, increasing aflatoxin exposure. Even within the same nation, aflatoxin- induced HCC risk can vary significantly among different populations, hence the large national ranges for risk shown in Table 4. Rural popula- tions generally have higher levels of aflatoxin exposure than do urban dwellers in developing countries (Wild and Hall 2000), because urban populations typically consume more diversified diets than do rural dwellers and may have food that is better controlled for contaminants. In addition, there is a strong seasonal variation in aflatoxin exposure that correlates with food availability (Gnonlonfin et al. 2008; Tajkarimi et al. 2007). Moreover, HBV prevalence is gen- erally higher in rural areas than in urban ones, and higher among males than among females in most places (Plymoth et al. 2009). We present our collected data of HBsAg seroprevalence as a Table 3. Estimated HCC incidence attributable to aflatoxin, by WHO region. WHO region/country Africa Democratic Republic of Congo Ethiopia The Gambia Kenya Mozambique Nigeria South Africa Tanzania Zimbabwe In generalc North America Canada United States In generalc Latin America Argentina Brazil Mexico In generalc Eastern Mediterranean Egypt Iran Pakistan Sudan In generalc Southeast Asia India Indonesia Thailand In generalc Western Pacific Australia China Malaysia Philippines Republic of Korea In generalc Europe Eastern Europe Southern Europe Western Europe In generalc Reference Manjula et al. 2009b Ayalew et al. 2006b Hall and Wild 1994; Shephard 2008 Hall and Wild 1994; Shephard 2008 Hall and Wild 1994 Bandyopadhyay et al. 2007; Bankole and Mabekoje 2004b Hall and Wild 1994; Shephard 2003 Manjula et al. 2009b IPCS/WHO 1998 Hall and Wild 1994; Shephard 2008 Kuiper-Goodman 1995 IPCS/WHO 1998 Etcheverry et al. 1999; Solovey et al. 1999b IARC 2002; Midio et al. 2001; Oliveira et al. 2009; Vargas et al. 2001b García and Heredia 2006; Guzmán-de-Peña and Peña-Cabriales 2005; Torres et al. 1995b Anwar et al. 2008b Hadiani et al. 2009; Mazaheri 2009b Munir et al. 1989b Omer et al. 1998 Vasanthi 1998 Ali et al. 1998; IARC 2002; Noviandi et al. 2001b Hall and Wild 1994; Lipigorngoson et al. 2003b NHMRC 1992; Pitt and Tomaska 2001 Li et al. 2001; Qian et al. 1994; Wang and Liu 2007; Wang et al. 2001b Ali et al. 1999; IARC 2002b Ali et al. 1999; IARC 2002; Sales and Yoshizawa 2005b Ok et al. 2007; Park et al. 2004 Malir et al. 2006e Battilani et al. 2008; Giray et al. 2007f IARC 2002 0.07–27 1.4–36 4–115 3.5–133 39–180 139–227 0–17 0.02–50 17.5–42.5 10–180 0.2–0.4d 0.26 0.26–1 0–4 0.23–50 14–85 20–50 7–57 5–8.5 7–50 19–186 10–80 4–100 9–122 53–73 30–100 0.15–0.18 17–37 15–140 44–54 1.2–6 15–50 (except Australia and New Zealand) 3.5–4 0–4 0.3–1.3 0–4 Global burden of aflatoxin-induced liver cancer range for countries or populations (Table 1), to account for these variations. Although many nations that suffer from both high aflatoxin exposures and high HBV prevalence have nominally established maxi- mum allowable aflatoxin standards in food, there is little if any enforcement of these standards in many rural areas. Indeed, the food in subsistence farming and local food markets is rarely formally inspected. Strict aflatoxin standards can even lead to large eco- nomic losses for poor food-exporting nations when trading with other nations (Wu 2004). Subsistence farmers and local food traders sometimes have the luxury of discarding Aflatoxin exposure (ng/kg body weight/daya) Estimated annual HCC (per 100,000) HBsAg-negative HBsAg-positive 0.0007–0.27 0.01–0.36 0.04–1.15 0.04–1.33 0.39–1.80 1.39–2.27 0–0.17 0.0002–0.50 0.18–0.43 0.10–1.80 0.002–0.004 0.003 0.003–0.01 0–0.04 0.002–0.50 0.14–0.85 0.20–0.50 0.07–0.57 0.05–0.09 0.07–0.50 0.19–1.86 0.10–0.80 0.04–1.00 0.09–1.22 0.53–0.73 0.30–1.00 ~0.002 0.17–0.37 0.15–1.4 0.44–0.54 0.01–0.06 0.15–0.50 0.04 0–0.04 0.003–0.01 0–0.04 0.02–8.10 0.42–10.8 1.20–34.5 1.05–39.9 11.7–54.0 41.7–68.1 0–5.10 0.06–15.0 5.25–12.8 3.0–54.0 0.06–0.12 0.08 0.08–0.3 0–1.20 0.07–15.0 4.20–25.5 6.0–15.0 2.1–17.1 1.50–2.55 2.10–15.0 5.70–55.8 3.00–24.0 1.20–30.0 2.7–36.6 15.9–21.9 9.00–30.0 ~0.05 5.10–11.1 4.5–42 13.2–16.2 0.36–1.80 4.5–15.0 ~1.20 0–1.20 0.09–0.39 0–1.2 NHMRC, National Health and Medical Research Council. aAssuming 60 kg body weight per individual. bAflatoxin exposure was estimated by multiplying aflatoxin concentrations in staple foods by consumption rates of those foods (WHO 2006). cAflatoxin exposure estimates and consequent HCC cases for all other countries classified in the same WHO region. dAflatoxin exposure of 1–2 ng/kg body weight/day was measured in children’s diets; here we assume the adult daily aflatoxin intake is 20% that of children. eAverage daily aflatoxin intake was estimated based on AFB1 contamination levels in Czech maize, multiplied by average daily maize consumption in Eastern Europe. fAverage daily aflatoxin intake was estimated based on AFB1 contamination levels in maize of North Italy and Turkey, multiplied by average daily maize consumption in Southern Europe. Environmental Health Perspectives • volume 118 | number 6 | June 2010 821