Bioaccumulation & Biomagnification of Toxicants Pat Ellsworth, ITEP Robert K. Hall U.S. EPA Region IX & Sherry Glick U.S. EPA U.S. EPA Office of Pesticide Programs

2 Bioaccumulation & Biomagnification: Introduction Bioaccumulation Bioaccumulation –Pollutant concentration increase from environment to first organism in food chain Biomagnification Biomagnification –Pollutant concentration increase from one food chain link to another

3 Bioaccumulation & Biomagnification: Introduction (cont.) For biomagnification to occur, pollutant must be For biomagnification to occur, pollutant must be –Long-lived –Mobile –Soluble in fats –Biologically active

4 Persistent Bioaccumulative Toxic (PBT) Chemical Program Program designed to identify, measure and prevent further risks to human health and environment from existing and future exposure Program designed to identify, measure and prevent further risks to human health and environment from existing and future exposure –Persistent –Bioaccumulative –Toxic (PBT) pollutants These pollutants pose risks These pollutants pose risks –Toxic –Persist in ecosystems –Accumulate up food chain

5 PBT Chemical Program (cont.) What makes a PBT? What makes a PBT? –Travels long distances –Transfers rather easily among air, water, land –Lingers for generations (long-lived in environment)

6 PBTs: What are they? Substances that resist environmental (i.e., hydrolyzation, photolyzation) and biological (e.g., microbial activity) degradation Substances that resist environmental (i.e., hydrolyzation, photolyzation) and biological (e.g., microbial activity) degradation Can cycle through several environmental media (e.g., water, soils, plants, animals, people) Can cycle through several environmental media (e.g., water, soils, plants, animals, people) Long residence time in environment – can travel long distances Long residence time in environment – can travel long distances Toxic (acute, chronic) to plants, animals, humans Toxic (acute, chronic) to plants, animals, humans

7 PBTs: Persistent Organic Pollutants (POPS) –Chemical substances (combustion byproducts or manufactured) resistant to chemical breakdown (i.e., persist) –Stored in body (i.e., bioaccumulate) –Cause adverse effects: acute, chronic, multi- generational (genetic – alter gene expression)

8 PBTs of Key Concern POPs (industrial processes, pesticides, by-products of combustion) POPs (industrial processes, pesticides, by-products of combustion) –Aldrin/Dieldrin, Chlordane, Mirex, Toxaphene, DDT (+DDD+DDE), hexachlorobenzene –PCBs, Dioxins/Furans Trace metals (natural sources; human-caused emissions) Trace metals (natural sources; human-caused emissions) –Mercury –Lead –Cadmium –Selenium

9 Effects of PBT Exposure POPs exposure POPs exposure –Endocrine disruption –Cancer –Birth defects, multigenerational reproductive challenges –Reduced immune function –Neurological

10 Effects of PBT Exposure (cont.) Trace-metal exposure Trace-metal exposure –Lead (learning and development) –Cadmium (renal failure (liver, kidney), itai-itai disease) –Selenium (teratogenic - birth defects) –Mercury (Neurological effects (learning and development, acute dose – teratogenic)

11 PBTs: Heavy Metals –Natural elements released by nature (e.g., volcanoes) and humans (e.g., mining, manufacturing) –Some are essential (e.g., zinc, manganese, selenium), some are not (mercury, lead, cadmium) –Stored in muscle, organs and bone. Not essential (Pb, Cd – Itai-Itai/osteo degeneration), replace Ca in bone –All metals toxic in high doses. Some essential trace metals toxic in extremely low doses (e.g., zinc, selenium, iron)

12 How are we exposed? Direct personal exposure to airborne PBTs from local sources Direct personal exposure to airborne PBTs from local sources –Diesel exhaust –Cigarette smoke –Cooking oils, product outgassing in indoor air –Cultural activities (e.g., cadmium in riparian plants) Exposure to long-range transported PBTs through food Exposure to long-range transported PBTs through food –Global pollution –PBTs enter and cycle through environmental media, bioaccumulate in wildlife

13 Mercury Pollution: Integration and Synthesis, Copyright Lewis Publishers, an imprint of CRC press.

14 From: Inuit Tapiriit Kanatami website FOOD CHAIN:

15 Trace-Metal Solubility SubstancesSolubility Product SubstanceSolubility Product Ba(OH) x FeS1.57 x SrSO x Cu(OH) x BaSO x Pb(OH) x Mn(OH) x PbS8.81 x MnS4.55 x Al(OH) x Cd(OH) x CuS1.28 x Zn(OH) x Fe(OH) x Fe(OH) x Cu 2 S2.24 x

16 What can you do?

17 National Inventories

18 Conclusion: Benefits and Risks of a Traditional Diet Risks Accidents – hunting/fishing Contaminants Benefits Health – reduced obesity, diabetes, heart disease Nutrition Taste Social-cultural value Cost Children’s education From Dr. Harriet Kuhnlein, CINE