EXPOSURE ASSESSMENT: CURRENT SITUATION IN THE PHILIPPINES

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Meryl Marshall
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1 EXPOSURE ASSESSMENT: CURRENT SITUATION IN THE PHILIPPINES

2 INTRODUCTION Risk assessments has grown significantly, even in developing countries, in light of the WTO s Agreement on the Application of Sanitary and Phytosanitary Measures. In this agreement it requires that sanitary and phytosanitary measures be based on scientific evidence.

3 As long as a country employs CODEX standards, its measures are presumed to be consistent with the provisions of the SPS Agreement CODEX standards were identified as key reference points in the WTO Agreement on the Application of Sanitary and Phytosanitary Standards (SPS) This reference to the Codex Alimentarius Commission is based on the underlying risk assessments that support Codex risk management decisions

4 DIETARY RISK ASSESSMENT One component of Risk Assessment is Exposure/Dietary Risk Assessment The degree of intake of food containing certain amount of residues considering food consumption data Dietary Risk assessment is usually the basis of MRL/MLs establishment with consideration of the Good Agriculture Practices (GAP)

5 Status of Risk Assessment in the Philippines FERTLIZER and PESTICIDE AUTHORITY (FPA) FPA, under PD 1144, has the authority to conduct a wide range of activities after a pesticide is registered in the country to assure that it is being handled, distributed and used in accordance to the rules and regulations of the PHILIPPINES. This include the risk assessment of pesticides.

6 Status of Exposure on Risk Assessment Just like in any other country, before a pesticide is registered, several data requirements are submitted to the Authority for basis of MRL establishment. The proposed MRLs are assessed for its dietary risk using national consumption data or GEMS Food Cluster data when no data is available for a specific commodity.

7 Status Cont d The FAO/WHO recommended to estimate national dietary exposures by using international toxicological reference value but national food consumption and concentration data. In addition to these data, there are other route of exposure to pesticides considered in the country aside from the Dietary Exposure, that is the Worker s exposure.

8 Status Cont d A. WORKER s EXPOSURE Monitoring data generated during exposure studies are used to determine the quantity of pesticides to which one is exposed after application and to develop the entry intervals Studies on toxicity using animal species and residue dissipation can also be used to address hazard to farm workers and applicators

9 STATUS CONT D B. DIETARY EXPOSURE Data generated from Supervised Residue Trials are used to estimate the dietary exposure of the general public to pesticide residues in food. FPA may allow residue data generated from other countries with similar agro-climatic conditions and use patterns. The proposed MRLs from supervised trials or monitoring data or CODEX MRLs are being evaluated for dietary risk using the local consumption data (whenever available) or international data (GEMS Cluster Diet)

10 GUIDELINES on DIETARY RISK /EXPOSURE ASSESSMENT MRL Establishment Legal Basis- FPA is mandated, under PD 1144, to establish a system of setting maximum residue limits (MRLs) applicable for both domestic and imported raw agricultural commodities in order to protect the public against potential hazards for pesticide residues in foods.

11 Exposure Assessment Cont d An exposure assessment is necessary in order to reach a conclusion on the acceptability of proposed MRLs and the underlying GAP from a public health point of view. The dietary intake of a pesticide residue in a given food is obtained by multiplying the residue level in the food by the amount of that food consumed. The total dietary intake of the pesticide residue is then obtained by summing the intakes of all foods containing the residue. 11

12 Dietary Exposure cont d The proposed MRLs from supervised trials or CODEX MRLs are being evaluated for dietary risk using the local consumption data (whenever available) or international data (GEMS Cluster Diet).

13 MRL ESTABLISHMENT FPA establish MRLs based on Supervised Residue Trials. It also adopts CODEX MRLs when no MRL has been established. Codex MRLs are used primarily to enforce and control compliance with nationally authorized uses of pesticides on commodities moving in international trade. The proposed MRLs are evaluated for its risk to consumers base on the calculations of the National Estimated Dietary Intake taking into account national food consumption and safety factors of pesticide residues

14 Dietary Intake Assessment Calculation NEDI= (FFi x C) wt. of an adult (kg) Where: NEDI National Estmated Dietary Intake (mg/kg bw) FF food factor (kg) i food in question C residue concentration or the proposed MRL (mg/kg)

15 Example: Insecticide X ADI=0.05 mg/kg bw Crop ffi (Kg) MRL (mg/kg) Ffi x MRL Rice Lettuce Milk All other crops 0.54 No MRL - total mg NEDI = mg = mg/kg b.w. 60 kg b.w Compare it with ADI: x 100 = 75%; No exceedance of the ADI 0.05

16 Example: Insecticide Y ADI is 0.01 mg/kg b.w. Crop ffi (Kg) MRL (mg/kg) Ffi x MRL Rice Lettuce Milk All other crops 0.54 No MRL - total mg NEDI = mg = mg/kg b.w. 60 kg b.w Compare it with ADI: x 100 = 375%. This exceeded the ADI 0.01

17 If there is exceedance of the ADI, it should not necessarily be interpreted as giving rise to health concern because of the conservative assumptions used in the assessment. However, risk managers have to make decision w/ member states once there is intake concern.

18 MONITORING OF PESTICIDES Data Generated in Monitoring Activities 1. Types of pesticides used 2. Report on incidence of poisoning 3. Extent of use of banned pesticides 4. Extent of pollution in the environment through fish kill, bird kill, contamination of ground water, and other manifestation of pesticide effects on public health and the environment

19 Monitoring Cont d Monitoring of pesticide poisoning activity is done to complete a risk assessment process in coordination w/ concerned agencies such as Municipal Health Centers, Provincial and Regional Officers, Dept. of Health and pesticide companies. Use Patterns- FPA ensure pesticide use in accordance to the labels.

20 Monitoring Cont d The Bureau of Plant Industry-The National Pesticide Analytical Laboratory is the monitoring arm of the FPA. NPAL monitors, for example, the residues that are in the positive list of Japan. Specifically, Japan rejects all mangoes that are positive for chlorpyrifos, profenofos, cypermethrin and endosulfan residues.

21 Compliance in Monitoring of Product Stewardship Quality- FPA has a mechanism to know if the product has expired, misbranded or adulterated Residues in foods- FPA has a monitoring system that provide information to assess the safety of the consumers. Environment- FPA w/ other concerned agencies (LGUs) and NGOs) monitor pesticide movement in the farms that may affect the fish and birds and other non target organisms

22 Other Toxicology Data- Human exposure and safety Labelling-Toxicity category Environmental fate and transport- adsorption, leaching, degradation in soil, hydrolysis, aqueous photolysis, analytical method for soil and water analysis.

23 Risk Assessment -Long Term Exposure The estimated long term dietary intake of pesticide residue are expressed as percentage of the ADI for a 60 kg person. - ADI is established on the evaluation of data on biochemical, metabolic, pharmacological, and toxicological properties of the pesticide derived from studies of experimental animals and observations in humans. The Philippines has not evaluated the short term intake of pesticide residues The estimated dietary intake of a residue is compared with its acute Rf D in the risk assessment

24 24 Guidelines for predicting dietary intake of pesticide residues Long Term Dietary Intake - Theoretical Maximum Daily Intake (TMDI). - International Estimate of Dietary Intake (IEDI) or National Estimate of Dietary Intake (NEDI)

25 Guidelines for predicting dietary intake of pesticide residues 25 Estimates of dietary intake play an important role in ensuring safe food for consumers throughout the world. Residue data are combined with cultural dietary information to make predictions of residue intake by the consumers.

26 Long-Term Dietary Intake 26 Long-term dietary intakes are calculated by multiplying the residue concentrations (STMRs,STMR-Ps or recommended MRLs) by the average daily per capita consumption estimated for each commodity on the basis of the GEMS/Food diets(culturak diets) and summing the intakes for each food.

27 27 Long-Term Dietary Intake Long-term dietary intakes are expressed as percentage of the ADI for a 60 kg person. When the percentage is higher than 100 for the compounds for which IEDIs are calculated, the information provided to the J MPR does not allow an estimate that the dietary intake would be below the ADI.

20. 6 Long-Term Dietary Intake (National Level) 28 National Theoretical Maximum Daily Intake (NTMDI) The NTMDI can be used to confirm the TMDI and incorporates factors available only at the national

28 20. 6 Long-Term Dietary Intake (National Level) 28 National Theoretical Maximum Daily Intake (NTMDI) The NTMDI can be used to confirm the TMDI and incorporates factors available only at the national level. W hen the NTMDI incorporating the Codex MRLs is below the ADI, national authorities may accept these MRLs. NTMDI = MRLi x Fi where: Fi = National consumption of that food commodity per person MRLi = Maximum Residue Limit (or national limit) for a given commodity

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30 Short Term Dietary Intake High intake of residues would occur when a large portion of a food with a high residue was consumed the residue level in a unit of fruit or vegetable ( i.e. a single apple or a single carrot) maybe substantially higher than the residue in a composite sample representing the typical residue in the lot. IESTI= LP x (HR or HR-P) bw 30

31 Summary of risk assessments of short-term dietary intake conducted by the 2004 JMPR Compound Codex code Name ADI (mg/ kg bw) Intake range (% of maximum ADI) 017 Chlorpyrifos IEDI 149 Ethoprophos IEDI 037 Fenitrothion IEDI 211 Fludioxonil IEDI 158 Glyphosate TMDI 049 Malathion IEDI 212 Metalaxyl/ Metalaxyl M TMDI 094 Methomyl IEDI 166 Oxydemeton methyl IEDI 057 Paraquat IEDI 112 Phorate TMDI 101 Pirimicarb TMDI Type of assessment 31

32 20.15 Summary of risk assessments of short-term dietary intake conducted by the 2004 JMPR Compound Codex code Name ARfD (mg/kg bw) Commodity Percentage of ARfD General population Children 6 years 096 Carbofuran All 20 commodities Chlorpyrifos 0.1 All 7 commodities Fenitrothion 0.04 Maize Wheat bran, unprocessed Wholemeal bread Fenpyroximate 0.01 Apple Grape Malathion 2 6 commodities Oxydemeton methyl Apple Cabbage, head Grape Orange 057 Paraquat All 44 commodities Prochloraz 0.1 Mushroom Propineb Pepper Pyraclostrobin 0.05 All 37 commodities

33 Factors for refining estimates of residue levels for predicting long-term dietary intake of pesticide residues at the national level. 33 National and International Median residue levels from supervised trials, including residue definition (see Section 3.2.1) Residues in edible portions (see Section 3.2.2) Effects of processing and cooking on residue levels (see Section 3,2.3) Other known uses of the pesticide (see Section 3.2.4) National Only Proportion of crop or commodity treated (see Section ) Proportions of crop or commodity produced domestically and imported (see Section ) Monitoring and surveillance data (see Section ) Total diet (market basket) studies (see Section ) Food consumption data, including for subgroups of the population (see Section 4.2.2)

34 Residues below LOD General rule- when residue trials are <LOD, the STMR would be assumed to be at the LOD, unless there is scientific evidence that residues are "essentially zero". Supporting evidence would include residues from related trials at shorter PHIs, exaggerated, but related, application rates or a greater number of applications, expectations from metabolism studies or data from related commodities. 34

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38 SUMMARY Risk Assessment of pesticides has grown significantly even in developing countries. In the Philippines, risk assessment process through the Fertilizer and Pesticide Authority considers both the toxicology and residues, in conjunction with the registration of a pesticide product. The risk of exposure to pesticides is considered by the authority through : a. workers exposure - to determine the quantity of pesticides to which one is exposed after application thereby determine the re-entry period of the workers and b. dietary exposure - to estimate the maximum amount of residues remaining in foods that will not exceed the Acceptable Daily Intake of man..

39 SUMMARY Cont d The residue data generated by companies based on Supervised Residue Trials should come up with a proposed MRLs. These are evaluated for its risk to consumers. Where no MRLs are established, the CODEX MRLs are adopted. Under the SPS, It recognizes that as long as a country employs the CODEX standards, its measures are presumed to be consistent with the provisions of the SPS Agreement. The National Estimate of the Dietary Intake (NEDI) is calculated by multiplying the concentration of pesticide (mg/kg) with the national consumption data (kg) considering the ave. weight of man (Kg). When there is exceedance of the Acceptable Daily Intake, it should not be interpreted as giving rise to health concern because of the conservative assumption used in the assessment but rather the risk managers should decide with the risk assessors on how to improve the risk assessment process using the GAP that will result to over estimation of the ADFI

Risk Assessment : A Philippine Experience on Pesticides for Food Safety. Amelia W. Tejada

Risk Assessment : A Philippine Experience on Pesticides for Food Safety Amelia W. Tejada CODEX and RISK ANALYSIS Risk Assessment hazard identification; hazard characterization; exposure assessment; risk