Health Risk from Consuming POC-Contaminated Fish: Part II. Risk Analysis and Prevention Strategies Michael H. Dong, MPH

1. Health Risk from ConsumingPOC-Contaminated Fish: Part II. Risk Analysis and Prevention Strategies Michael H. Dong, MPH, DrPA, PhD October, 2007 Readings

2. taken at the Epcot Center, Orlando, Florida, USA

3. Lecture Objectives • Appreciate the POC residue levels in fish observed in various countries. • Compare these real-time residue levels to their respective screening values that have been adopted as threshold levels. • Revisit the basic strategies used for preventing health risk from consuming fish contaminated with POCs.

4. Performance Objectives • Students are expected to know that worldwide levels of some POCs are still far exceeding their screening values. • . . to know what the methodological issues and associated uncertainties are in the risk analysis conducted here. • . . to know that the prevention strategies so discussed can be costly, yet crucial.

6. Advisory for High Risk Groups • A considerable number of monitoring sites were noted to have POC levels > the screening values by 30-fold+. • For these areas, no more than 1 or 2 fish meals/month should be recommended. • Fish advisories of this kind may not be all that practical to residents who rely on fish as their main diet.

7. Issues Inherent in the Analysis • Risk analysis of the type conducted here is far from flawless. • High consumption observed may not correlated well with high residue level detected even in the same vicinity. • Nor are all fish species in the same vicinity necessarily contaminated by the same chemical or to the same extent.

8. Other Related Issues (I) • The characteristics, the transport, and the fate of POCs present in the aquatic environment all can play a crucial role. • Current trends may not be indicative of the POC levels in fish in the future. • For example, some POCs have been transported to remote sites where the chemicals have never been used.

9. Other Related Issues (II) • There are also uncertainties with the empirical data used in the analysis. • All tolerance limits or screening values are based on the toxicity data on hand, which are ever lacking or indirect. • Residue data are vulnerable to technical errors inherent in sample collection and in the analytical procedures used.

10. Implications of Analysis Data • While both the tolerance levels and the POC residue data must be applied with caution, some level of conservatism could/should still be exercised to err on the side of health protection. • Certain prevention strategies are thus warranted here for fish contamination with POCs in many localities.

11. Concerns with Bioaccumulation • Bioaccumulation refers to cumulative and aggregate exposures during the same time interval. • Its occurrence in humans can lead to further alarming health consequences. • The main concern here is that fish and shellfish are not a person’s only source of exposure to the same/a similar POC.

12. Issues with Bioaccumulation • Once a lipophilic chemical (e.g., POC) is inside the human body, it will not go away any time soon. • A large enough single dose (exposure) can induce an acute adverse effect. • The ADI or RfD used might not have taken into account the extra amount of a POC coming from other sources.

13. A Case of Bioaccumulation • A pregnant woman was exposed to a POC daily at a constant dose of 10 units from fish consumption, and 5 units through other sources (e.g., milk, water). • Then on day 10, this woman would have as her body burden a total of 150 (not 100) units of this chemical, which would exceed the threshold of 100 units.

14. Risk Prevention Strategies • Certain risk prevention strategies hence should be in place to cope with the potential hazard from consuming fish contaminated with POCs. • These would involve: environmental health policy; regulatory/research activities; residue monitoring programs; and self awareness/prevention.

15. Environmental Health Policy • Programs/policies should be developed, with a focus on better use of POCs and on better handling of waste removal. • FQPA-like laws should be adopted to focus on children’s higher sensitivity. • Governments should have available more, as well as more effective, POC-related illness surveillance programs.

16. Regulatory/Research Activities • Activities should be in place to enrich risk communication resources for fish contamination with POCs. • Research is needed to refine the works done on risk assessment methodology, on toxicity studies, and on relevant exposure parameters including fish consumption pattern.

17. Residue Monitoring Programs • More monitoring programs for POCs in fish need to be developed around the ‘hot spot’ areas (which should be more aggressively identified). • These programs should be effective with a special focus on sampling, on the analytical technique used, and on uniform reporting of monitoring data.

18. Self Awareness/Prevention (I) • Awareness/prevention at the individual level is the most effective approach to minimizing the human health risk from consumption of POC-contaminated fish. • This assertion is based upon the notion that risk prevention at the individual level is much more tangible, more controllable, and thus more attainable.

19. Self Awareness/Prevention (II) • A fish consumer should make every effort to choose younger fish to eat. • The person should remove the fish’s guts as these are the organs where some POCs also tend to concentrate in. • The person should also trim the fish’s fat, remove the skin, and cut away the fatty dark meat.

20. Self Awareness/Prevention (III) • Lastly, the consumer should cook fish in a way that would allow the fat to drip away or drain off. • This can be accomplished effectively with most cooking methods. • Up to 60% or more of the POCs could be reduced by the way in which the fat is dripped or drained away.

21. Self Prevention with a Price • In closing, it is fair to forewarn that the type of self risk prevention measures suggested here is not without a price, unless fish can swim in or be cultivated in a cleaner aquatic environment. • Otherwise, the individual consumers would end up getting less intake of the good (i.e., the essential) fats in fish.