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Aflatoxin Country Assessment for Tanzania
Abt Associates, Inc.
December 3, 2012
Abt Associates | pg 2
Objectives of the Country Assessment in Tanzania
To characterize the risks and economic impacts of aflatoxin contamination…
…and to identify promising opportunities for control.
Abt Associates | pg 3
A Conceptual Framework for Aflatoxin Country Assessment
Identify Key Crops of Concern
High Production High Consumption High Value
Step
1
Determine Prevalence of Aflatoxin
Geographical area of Concern Percent Contamination Degree of Contamination
Step
2
Characterize Risks of Aflatoxin Contamination and Exposure
Uses of Crop Risks along Value Chain
Step
3
Estimate Economic Impacts
Agriculture and Food Security Trade
Step
4 Health
Identify Opportunities for Aflatoxin Control
Institutional, Legal and Regulatory Review Control Strategies in Agriculture Trade and Health
Step 5
Abt Associates | pg 4
Data Sources Tanzania 2008-2009 General Household Panel Survey part of the
World Bank’s Living Standards Measurement Study Integrated Surveys on Agriculture (LSMS-ISA) project that has nationally and zonally representative data on household consumption, anthropometry, agricultural production and sales, use of inputs and extension services, and constraints to agricultural production.
Field Research in three locations from different agro-ecological zones – Njombe, Irenga; Bukombe, Shinyanga; Kongwa, Dodoma
Interviews with Ministries and stakeholders in Dar es Salaam, interviews in three rural areas
Secondary Data
– Published and unpublished articles
Abt Associates | pg 5
Key Crops of Concern Maize is the most important agricultural crop in Tanzania in terms of
quantity and value of production, followed by cassava
Groundnuts are important because of its promotion in weaning foods
Milk and cassava are two other potential commodities that could be assessed with additional funding.
Data Source: CountrySTAT, Year, 2010
Step1
Abt Associates | pg 6
Aflatoxin PrevalenceStep2
Zone NB1 Total
Share >LOD1 Mean if detected (ppb) Share >LOD2 Mean if detected
(ppb)Maize
Eastern 40 58% 37.26 68% 46.33North 65 15% 11.03 34% 11.77South 40 3% 1.00 23% 1.84Southern Highlands 99 12% 4.74 38% 4.30West 30 70% 16.51 90% 31.71National 274 24% 20.48 45% 24.30
GroundnutsNorth 20 30% 14.42 100% 7.69South 40 33% 11.80 88% 9.74West 40 35% 10.72 98% 7.50National 100 33% 11.82 94% 8.30
LOD = Limit of Detection; ppb = Parts per Billion
Abt Associates | pg 7
Prevalence of Aflatoxin B1 in Groundnuts
Abt Associates | pg 8
Prevalence of Aflatoxin B1 in Maize
Abt Associates | pg 9
Characterization of Risks Whether the risks of aflatoxin-contamination are
greater on a country’s agriculture and food security, trade and/or health is determined by:
– (1) the uses of aflatoxin-contaminated crop (whether primarily for domestic human consumption, international trade, or feed use);
– (2) levels of awareness about aflatoxins and aflatoxin control among farmers, traders, and consumers;
– (3) the application of tolerances within the food marketing system and types of actions taken by regulators and buyers to mitigate the risk.
Step3
Abt Associates | pg 10
Uses of Maize and Groundnut
Production
Own Consumption Sale to Market
Market Loss Discarded grain Reduced prices Litigation
Human Health Impact Disease burden Reduced productivity
Market Loss Reduced milk productivity Livestock disease burden Reduced prices of products Discarded products.
Contaminated Livestock Products
Livestock Feed
Contaminated Products
Majority of the maize crop in Tanzania is used for direct human consumption (FAOSTAT 2009).
– 68 % -human consumption, – 19 % feed, – 12 % other residual uses, – 2% re-planting
Average agricultural households report selling 17 % of their maize produce, 2 % for feed, using 1 % for seed, and the residual 77 % for own consumption or storage (LSMS-ISA, 2008/9).
Of the 270 MT of groundnut production, 51 % was used directly as food, and 38 %was used for other purposes (FAOSTAT 2009).
Abt Associates | pg 11
Characterization of Risks along the Value Chain
•Are Good Agricultural Practices known and used?
•What is the awareness level of farmers?
Agriculture
•Are there regulations on aflatoxins for commerce?
•Are the regulations enforced?
•Are traders aware about aflatoxins?
Trade• Are the consumers
aware about aflatoxins?
• Do feeding practices contribute to health risks?
Health
ForktoFarm
Abt Associates | pg 12
Agriculture –Risk of Contamination
Analysis of nationally representative data (LSMS/ISA) suggests that the use of Good Agricultural Practices (GAP), which improve plant health and prevent aflatoxin contamination is low
– PESTICIDE USE: 11% for maize and 3% for groundnuts
– IMPROVED SEEDS: 18% for maize and 3% for groundnuts
– FERTILIZER USE: 17% for maize and 1% for groundnuts.
– IRRIGATION: Only 2% of cultivated area under maize is irrigated, negligible for groundnuts
Qualitative field research in three districts suggests that
• Drying of crops is typically done on the ground
• Storage units are rudimentary (No household report using modern structures for groundnuts, 12% use traditional structures, and 78% use sacks/open drums, 1% -4% report using improved structures for maize, 19% use traditional structures and 64% use sacks/open drums.)
• There are few means for moisture measurement and control
Abt Associates | pg 13
Agriculture –Risk of Contamination
Awareness among farmers about the causes and consequences of aflatoxins is low or non-existent.
Agriculture extension systems do not have a set agenda for aflatoxin messaging.
Use of extension systems is low (only 19% of the households report using government extension system).
Farmers do some basic sorting and drying to gain price premium for better sorted grain.
There is an opportunity in Directorate of Food Security, and the planned expansion of extension agents by 11,000.
Abt Associates | pg 14
Trade –Risk of Contamination in Market
Tanzania Bureau of Standards has set standards for maximum aflatoxin (and mycotoxin) concentrations in food products, Tanzania Food and Drugs Authority enforces these standards – but it is effective only for packaged goods and export-bound products
Field research and interviews with stakeholders suggest that there is no testing for aflatoxins in the domestic market.
Awareness about aflatoxins is low among sellers (and buyers).
Interviews with maize millers in Njombe indicated that if farmers bring poorly sorted maize it goes through further sorting at farmer’s cost, but without any specific attention to achieving aflatoxin standards.
Since there is no mandate for withdrawal and destruction of contaminated commodities, grain deliveries rejected by large commercial operations will likely be sold by a trader to smaller feed manufacturers that do not test for aflatoxin.Overall, it appears that aflatoxin-contaminated products could enter the domestic
market without any cost to the producers, traders and retailers.
Abt Associates | pg 15
Health –Risk of Aflatoxin Exposure
Consumers’ level of aflatoxin knowledge is very low in Tanzania and exacerbated by the large share of maize in household diets.
There is heavy reliance on maize-based porridges during a child’s weaning stage.
A large share of maize consumption comes from own production for agricultural households (63 %).
Share of Foods in Weekly Calorie Intake of Households
Abt Associates | pg 16
Key Risk and Expected Impact of Aflatoxin Contamination in Nigeria
Greatest risk and impact on:
Health
Low awareness among farmers,
traders and consumers.
Majority of maize and groundnuts is
consumed domestically
Low enforcement of existing regulations on aflatoxins/mycotoxins
Abt Associates | pg 17
Economic Impact-Agriculture and Food Security
There is negligible to no aflatoxin control by farmers, yet absence of price premium for aflatoxin-free maize implies that there are no actual market losses to producers or traders of primary commodities destined for direct human consumption.
On the other hand, suppliers of susceptible commodities--maize, groundnuts-used for export market in poultry or fish feed may suffer absolute or partial rejections as well as price penalties.
Step4
Abt Associates | pg 18
Economic Impact-Agriculture and Food Security (continued)
All four pillars of food security are affected but not perceived
• Availability -- Aflatoxin-free maize and groundnuts is impacted by this challenge but not recognized by consumers or food markets.
• Access – Farmers generally do not yet incur loss in farm revenue because of aflatoxin-contamination in their grain. Use of aflatoxin control will imply increased production costs, that may be tempered by premiums on aflatoxin-free crop
• Utilization – The largest impact of contamination is on human consumption of unsafe and possibly less nutritious products that arises due to lack of aflatoxin control and lack of awareness
• Stability – Since aflatoxins are dependent on climactic conditions, stability in the other three pillars will vary with prevalence
Step4
Abt Associates | pg 19
Food Security : Availability and Access
Step4
Exhibit 6 2: Percentage Contribution of Groundnut and Maize on Food Availability and Access for ‑Agricultural Households
Food Availability (Percentage from Own Production)
Food Access (Percentage Contribution to Agricultural
Income)
Zone Maize Groundnuts Maize Groundnuts
Central 73% 77% 9% 10%
Eastern 44% 30% 2% 14%
Lake 61% 79% 2% 6%
North 42% 18% 0% 17%
South 82% 80% 7% 13%
Southern Highlands 71% 67% 3% 19%
West 61% 75% 5% 6%
Zanzibar 1% 12% 12% 8%
National 63% 72% 9% 10%
Source: Estimated from LSMS-ISA (2008/9)
Abt Associates | pg 20
Food Security: UtilizationStep4
Exhibit 6 1: Calorie Intake Share of Foods by Key Zones in Tanzania‑
Zone Cashew Cassava Groundnut Maize
Milk and milk
productsRice
All Other Crops
Central 0% 1% 8% 43% 1% 5% 41%Eastern 0% 6% 1% 31% 1% 20% 41%Lake 0% 14% 3% 32% 2% 7% 43%North 0% 4% 1% 46% 4% 8% 37%South 1% 26% 3% 35% 0% 9% 27%Southern Highlands 0% 6% 3% 55% 1% 6% 28%
West 0% 9% 5% 51% 1% 11% 23%Zanzibar 0% 9% 1% 8% 1% 37% 45%National 0% 9% 3% 41% 2% 10% 34%Source: Estimated from LSMS-ISA (2008/9)
Abt Associates | pg 21
Utilization: Calorie Intake by zones.
Zone Cashew Cassava Groundnut Maize
Milk and milk
productsRice
All Other Crops
Central 0% 1% 8% 43% 1% 5% 41%
Eastern 0% 6% 1% 31% 1% 20% 41%
Lake 0% 14% 3% 32% 2% 7% 43%
North 0% 4% 1% 46% 4% 8% 37%
South 1% 26% 3% 35% 0% 9% 27%Southern Highlands 0% 6% 3% 55% 1% 6% 28%
West 0% 9% 5% 51% 1% 11% 23%
Zanzibar 0% 9% 1% 8% 1% 37% 45%
National 0% 9% 3% 41% 2% 10% 34%
Source: Estimated from LSMS-ISA (2008/9)
Abt Associates | pg 22
Trade Impact Domestic Trade
– Farmers incur some cost for basic sorting to respond to this price differentiation.
– Some degree of price differentiation for quality exists and farmers face loss for additional cost of sorting required by millers.
– However, the differentiation is not because of aflatoxin or mycotoxins
– Our field research found no domestic testing and awareness of aflatoxins/mycotoxins for direct human consumption
Therefore, given the current conditions, there is negligible, if any, domestic market impact of aflatoxin contamination.
Abt Associates | pg 23
Trade Impact in Groundnuts
Historically the export share was as high as 27 percent, but has now settled to between 2-6 percent.
There were no aflatoxin related alerts in EU alerts and rejection system in the last 5 years.
EU harmonization of aflatoxin standards was in 1998.
An ICRISAT study notes that the key constraints to groundnut production unfavorable weather, management skills, access to credit, pests, diseases, access to inputs, management.
Tanzania can gain from investing in improving groundnut production to compete in the international trade market. However, aflatoxins are not the only reason Tanzania has not entered this market so far.
19611964
19671970
19731976
19791982
19851988
19911994
19972000
20032006
20090
50,000
100,000
150,000
200,000
250,000
300,000
0.0%
5.0%
10.0%
15.0%
20.0%
25.0%
30.0%
35.0%
Groundnut Production (Tonnes)Share in World Export (%)Export Share in Production
Tonn
es
Abt Associates | pg 24
Trade Impact in Maize
Historically maize exports have been low. Maize exports have often been banned--as they are now--
because of this crop’s importance for food security.
Constraints other than aflatoxin contamination is limiting export of maize from Tanzania.
19611963
19651967
19691971
19731975
19771979
19811983
19851987
19891991
19931995
19971999
20012003
20052007
20090%
1%
2%
3%
4%
5%
6%
7%
0
500,000
1,000,000
1,500,000
2,000,000
2,500,000
3,000,000
3,500,000
4,000,000
4,500,000
5,000,000
Maize Production (Tonnes) Export Share in Production
Abt Associates | pg 25
Health Impact Arguably the largest are of impact of aflatoxin
contamination in Tanzania.
Conclusive evidence of health impact of aflatoxin is established for liver cancer – this is quantified and monetized in the country assessment for a range of aflatoxin prevalence values.
Impact on stunting is still inconclusive, with only one article establishing the relationship between aflatoxin contamination and stunting
Abt Associates | pg 26
Estimating Health Impact
Aflatoxin Contamination
(ng/g)
Consumption(gram/day)
Body Weight(kg)
Exposure to Aflatoxins
(ng/kg-bw/day)
Shares of HBV
positive population
Liver Cancer Cases
(number/year)
Exposure to Aflatoxins
(ng/kg-bw/day)
Population(2010
projected) Share of HBV
positive population
Cancer Potency for HBV Positive
(0.3 per 100,000)
Cancer Potency for HBV Negative
(0.01 per 100,000)
Sum of:
Population Risk (Cancers/year/
100,000
Abt Associates | pg 27
Consumption of Maize
Abt Associates | pg 28
Consumption of Groundnuts
Abt Associates | pg 29
Sensitivity Analysis of ImpactsEstimated the impact with varying contamination.Even at 10 ppb the current consumption levels of maize implies that 1092 out of 1209 liver cancer cases can be attributed to aflatoxins.
In another sensitivity analysis, we estimate that if HBV prevalence is reduced to zero, the total number of liver cancer cases attributed to aflatoxins would reduce 3-fold
Zone
Maize and GroundnutConsumption (g/person(60kg)/day)
Aflatoxin Contamination (ppb)1 4 10 20 50 100
Central 367 9 36 90 181 452 903
Eastern 261 11 46 115 230 575 1,150
Lake 278 15 60 149 298 746 1,491
North 362 17 68 171 342 854 1,708
South 299 8 32 81 162 406 812
Southern Highlands
495 20 81 203 406 1,015 2,030
West 508 28 111 277 554 1,385 2,770
Zanzibar 66 1 2 6 11 28 55
National 521 109 437 1,092 2,184 5,460 10,920
Abt Associates | pg 30
Opportunities for Aflatoxin Control in Africa
Institutional, Policy and Regulatory Environment Setting and publicizing clear division of roles and responsibilities may
yield greater regulatory efficiencies.
Leverage existing opportunities in newly formed strategies (e.g. agriculture, nutrition) and develop guidance that incorporates mycotoxins.
Each agency should also agree on a coordinated, risk-based surveillance strategy to communicate and isolate threats to the food system.
Changing the mandates of TBS, TFDA, and other specialized agencies to regulate raw commodities destined for domestic consumption.
Set procedures for withdrawal of contaminated samples and explore alternative uses for contaminated products.
Strengthen the institutional mandate for cross-ministerial collaboration in shifting production and consumer demand for food quality.
Step5
Abt Associates | pg 31
Opportunities for Aflatoxin Control in Africa
Scale public and private sector initiatives to increase access to and adoption of aflatoxin-reducing agricultural inputs and practices, e.g. scaling up targeted input voucher programs for the poorest farmers.
Capitalize on mobile technologies and banking services to design business models for agricultural inputs that serve the poor.
Use bio-controls such as the IITA-developed Aflasafe approach or natural fungicides to reduce aflatoxin levels in soil and among treated crops, even after poor storage.
Introduce simple yet effective post-harvest techniques such as drying above ground or using economical solar driers to reduce adverse conditions that favor growth
Introduce improved storage methods and materials such as hermetic storage toarrest development of the responsible Aspergillus species
Use national data on agricultural stressors to target market-based solutions to address localized threats.
Use the global research agenda on aflatoxin to inform and complement domestic research, and vice versa
Agriculture
Abt Associates | pg 32
Opportunities for Aflatoxin Control in Africa
Raise awareness of tolerances and associated SPS practices in foreign markets of interest, and improve the capacity of grower/shippers and exporters to assure compliance
Spearhead harmonized SPS policies within East Africa that tend to reduce the mycotoxin problem (both aflatoxins and fumonisins) while facilitating cross border trade
Explore alternative uses for contaminated crops that make sense for Tanzania, and adjust official standards accordingly
Use economic incentives to shift behaviors in the supply chain while simultaneously expanding access by farmers to the best aflatoxin control solutions
Encourage the use of improved storage systems at all levels that reduce deterioration and loss, coupled with warehouse receipts programs that facilitate usage of commercial or community-managed storage as well as actions by the commodities exchange board and marketing boards (if revived) to preserve the quality, condition, and safety of agrifood products destined for human consumption
Leverage the formation of marketing boards for Cereals and other products that includes maize and groundnuts.
Trade
Abt Associates | pg 33
Opportunities for Aflatoxin Control in Africa
Encourage dietary diversity based on non-susceptible plant and animal products
Carry out joint campaigns between the Ministries of Health and Agriculture to raise consumer demand for good agricultural practices that lead to safer food
Improve awareness of human nutritional requirements, especially for pregnant and lactating women and during the first 1,000 days of life
Foster changes in household feeding/weaning and food use/preparation practices through behavioral change communications
Upgrade the food safety control system. particularly as it affects human health/welfare. i.e. policies and standards for mycotoxins/aflatoxins that take into account average daily intake, surveillance and testing methods, withdrawal/compensation procedures, penalties for infringements
Stay current on global research on the linkages between aflatoxins and health/nutrition while exploring avenues for further research of particular relevance to Nigeria
Pursue universal access to the HBV vaccine.
Health
Abt Associates | pg 34
Conclusion Aflatoxins are carcinogens w/other health effects
Contamination can interfere with trade & commerce
Believed to impact all of Africa, including Tanzania
Cost of inaction is high, especially in human health
Range of solutions is broad, but resources scarce
Prioritization and customization is needed
Mitigation should be multi-sectoral and coordinated