Daniel et al. During the outbreak years, homegrown maize aflatoxin contamination was extremely high, whereas maize production was low or nonexistent. In 2007, when maize production dramatically increased, homegrown maize aflatoxin levels were low. The nature of crops under drought conditions may be the rea- son for this association. During periods of drought, crops are stressed and become more prone to aflatoxin contamination (Wilson and Payne 1994). In addition, food scarcity may promote improper farming practices such as harvesting maize while wet to ensure it would not be stolen (Azziz-Baumgartner et al. 2005), thus increasing the opportunity for fungal growth and aflatoxin contamination. Efforts to address food security during periods of drought should be linked to heightened food safety efforts to prevent consuming aflatoxin- contaminated food. Although many maize samples had extremely high levels of aflatoxins, < 2% of the study population consuming this maize had jaundice at the time the questionnaire was administered. In fact, jaundice was not docu- mented in households where maize levels were the highest (48,000 ppb and 24,400 ppb), highlighting that factors associated with devel- oping aflatoxicosis after aflatoxin exposure are not fully characterized. Our findings suggest that chronic exposure to aflatoxin may be sub- stantial and widespread in this region; the risk posed to public health is potentially great but not defined in this setting. The International Agency Research on Cancer (IARC) has classi- fied aflatoxin as an established human carcino- gen (IARC 1987), especially with co-existing chronic hepatitis B infection (IARC 1993; Wild and Montesano 2009; Williams et al. 2004). In the Kenyan population, in particular, it is estimated that approximately 70% of Kenyans have a positive hepatitis B virus serology by adulthood (Mphahlele et al. 2002). In addition, recent studies have shown decreased immune function among populations exposed to afla- toxin (Jiang et al. 2008). Although outbreaks of acute aflatoxicosis with associated high case-fatality rates command the attention and resources of governments and foreign aid agen- cies, assessing the effect of chronic exposure and implementing effective interventions to mini- mize chronic aflatoxin exposure is needed. The Kenyan government expends sub- stantial resources to educate farmers about the sources of aflatoxin contamination and proper drying and storing practices. Other studies have shown the benefits of education and awareness (Hell et al. 2000; James et al. 2007). Our study shows a significant increase of aflatoxin aware- ness over time. However, we found no signifi- cant association between maize aflatoxin levels and awareness, suggesting that the information provided may not translate to actions to change current maize harvest and storage practices. 1798 During drought periods, contamination may be more ubiquitous and beyond the control of individual farmers. Awareness of aflatoxin prevention methods without the accompany- ing agricultural infrastructure to effectively dry and store maize may not translate to behavioral changes that would prevent or mitigate the extent of contamination. Our findings show that 35% of maize sampled in 2005, 2006, and 2007 exceeded the 20-ppb Kenyan regulatory limit with lev- els as high as 48,000 ppb. Previous studies suggest that the levels of aflatoxins found in homegrown maize in this region of Kenya are more than 60 times greater than the maximum maize aflatoxin levels found in other regions of the world. In a recent survey of published literature, we found a study by Williams et al. (2004) about aflatoxin contamination of mar- ket samples of foods from more than 20 coun- tries. It showed that the maximum aflatoxin levels found in maize or corn products was 770 ppb in Nigeria, followed by 465 ppb in corn from Mexico (Williams et al. 2004). In addi- tional studies done in neighboring Tanzania, aflatoxin levels in home-stored maize reached up to 158 ppb (Kimanya et al. 2008). Levels in other African regions measured in market stores reached 120 ppb in Benin, 490 ppb in Ghana, and 110 ppb in Togo (Hell et al. 2000; James et al. 2007). This demonstrates that the region of Eastern Kenya has a unique challenge with aflatoxins that deserves further exploration (Probst et al. 2007). Additionally, prevention efforts such as improving infra- structure for drying and storing and systematic screening and food monitoring may be neces- sary to minimize exposure to contaminated maize at the subsistence farm level. Limitations. Our findings should be inter- preted in light of some limitations. Our analysis included data collected from three individual public health responses. Sampling methodology varied by year. To address this, we conducted separate analyses by year, and when combining data from all 3 years we adjusted for year. In addition, the health information collected on the presence of jaundice was self-reported. Conclusions Eating highly contaminated maize has resulted in outbreaks of acute aflatoxin poisoning for > 20 years in a localized area in Kenya (Azziz- Baumgartner et al. 2005; Ngindu et al. 1982). This study is the first to explore the potential sources of aflatoxin exposure by comparing levels in the various sources of maize avail- able to this high risk population. These data show that homegrown maize had significantly higher aflatoxin levels than other sources (pur- chased or relief); however, purchased samples also had very high levels. Future prevention efforts to reduce aflatoxin exposure should target this high-risk population. c ectinor In Table 4 of the manuscript originally published online, the values for n (%) were transposed for “All years combined.” The table has been corrected here. Ref Rencs Association of Official Analytical Chemists (AOAC). 2005. Official Methods of Analysis. AOAC International (OMA). Home page. Available: http://www.eoma.aoac.org/ methods/info.asp?ID=10654 [accessed 15 February 2011]. Azziz-Baumgartner E, Lindblade K, Gieseker K, Rogers HS, Kieszak S, Njapau H, et al. 2005. Case–control study of an acute aflatoxicosis outbreak in Kenya. Environ Health Perspect 113:1779–1783. CDC (Centers for Disease Control and Prevention). 2004. Outbreak of aflatoxin poisoning—eastern and central provinces, Kenya, January–July, 2004. MMWR Morb Mortal Wkly Rep 53:790–793. Eaton DL, Groopman JD, eds. 1993. The Toxicology of Aflatoxins: Human Health, Veterinary, and Agricultural Significance. London:Academic Press. FDA (Food and Drug Administration). 2000. Guidance for Industry: Action Levels for Poisonous or Deleterious Substances in Human Food and Animal Feed. Available: http://www. fda.gov/Food/GuidanceComplianceRegulatoryInformation/ GuidanceDocuments/ChemicalContaminantsandPesticides/ ucm077969.htm#afla [accessed 20 May 2011]. Gitu KW. 2004. Agricultural Development and Food Security in Kenya: Building a Case for More Support. Available: www. fao.org/tc/TCA/work05/Kenya.pdf [accessed 1 February 2011]. Hell K, Cardwell KF, Setamou M, Poehling HM. 2000. The influ- ence of storage practices on aflatoxin contamination in maize in four agroecological zones of Benin, West Africa. J Stored Prod Res 36:365–382. IARC (International Agency for Research on Cancer). 1987. Aflatoxins. In: Overall Evaluations of Carcinogenicity. IARC Monogr Eval Carcinog Risks Hum 1–42(suppl 7):83–87. IARC (International Agency for Research on Cancer). 1993. Aflatoxins. In: Some Naturally Occurring Substances: Food Items and Constituents, Heterocyclic Aromatic Amines, and Mycotoxins. IARC Monogr Eval Carcinog Risks Hum 56:245–395. James B, Adda C, Cardwell K, Annang D, Hell K, Korie S, et al. 2007. Public information campaign on aflatoxin contamina- tion of maize grains in market stores in Benin, Ghana, and Togo. Food Addit Contam 24:1283–1291. Jiang Y, Jolly P, Preko P, Wang J, Ellis W. 2008. Aflatoxin- related immune dysfunction in health and in human immunodeficiency virus disease. Clin Dev Immunol 2008; doi:10.1155/2008/790309 [Online 5 August 2008]. Kenya Bureau of Standards. 1988. Dry-milled maize products. Kenyan Standard No. 05158. Nairobi:Kenya Bureau of Standards. Kenya Integrated Household Budget Survey (KIHBS). 2005/2006. Basic Report (Revised Edition). Available: http://www. knbs.or.ke/pdf/Basic%20Report%20(Revised%20Edition). pdf [accessed 19 January 2008]. Kimanya ME, De Meulenaer B, Tiisekwa B, Ndomondo-Sigonda M, Devlieghere F, Van Camp J, et al. 2008. Co-occurrence of fumonisins with aflatoxins in home-stored maize for human consumption in rural villages of Tanzania. Food Addit Contam Part A Chem Anal Control Expo Risk Assess 25:1353–1364. Lemeshow S, Robinson D. 1985. Surveys to measure programme coverage and impact: a review of the methodology used by the Expanded Programme on Immunization. World Health Stat Q 38:65–75. Lewis L, Onsongo M, Njapau H, Shurz-Rogers H, Luber G, Kieszak S, et al. 2005. Aflatoxin contamination of commer- cial maize products during an outbreak of acute aflatoxico- sis in Eastern and Central Kenya. Environ Health Perspect 113:1763–1767. Mphahlele MJ, Francois G, Kew M, Van Damme P, Hoosen AA, Meheus A. 2002. Epidemiology and control of hepatitis B: implications for eastern and southern Africa. South Afr J Epidemiol Infect 17:12–17. ovlume 119 | number 12 | December 2011 • Environmental Health Perspectives