TOXIC SUBSTANCES ENSC 202 Stephanie DiBetitto, Josh Fontaine, and Rebecca Zeyzus

LCB’s Proposed Toxic Substance Problems

3 Subcategories of Toxic Substances Heavy Metals Organochlorines: PCBs, dioxin, DDT Others: VOCs, PAHs, phthalates Substances within these subcategories are posing threats to the LCB

Problem Many sources (industry, deposition, agriculture, WWTP, etc.) Many sources contributed from outside LCB Transported through ecosystems Synergistic effects Harmful to many areas of life Can be persistent within the environment

Objectives To evaluate negative impacts of the substances of concern To identify and document the toxic substances’ source, and their modes of transport between habitats and through ecosystems To examine the risk presented within the habitats and the link between the sources and toxins persisting within the environment

Goal/ Purpose To understand the potential risk posed by the three subcategories of toxic substances within ecosystems Apply the findings to a relative risk model for the Lake Champlain Basin in the future

(Methyl- Hg) NIOSH REL: 0.05 mg/m 3

NIOSH REL: mg/m 3

Figure 2. Surface sample trace metal concentrations (from partial digestion) and TEL, ER-L, PEL, ER-M values. The height of the bar represents the trace metal concentration or guideline value in gg − 1. The stations are arranged in roughly a north-south orientation. (Lacey et al., 2001)

Figure 7. Core samples: trace metal concentrations from partial digestion (g g−1) versus depth (cm)below sediment/water interface. The cores are presented in roughly a northwest-southeast transect (Lacey et al., 2001)

General Findings: Organochlorines Significantly impact the environment and human health at low concentrations Highly toxic Highly mobile Persistent Hydrophobic Lipophilic  bioaccumulate Endocrine disruptors

Sources: Organochlorines *Atmospheric Deposition Agricultural and Urban Runoff Waste Water Treatment Industrial Waste Discharges

Chemical Characteristics: Organochlorines Semi- volatile Low vapor pressure Undergo diffusion, advection, and convection Co-exist in both gas and particle phases, cycle through the atmosphere and earth’s surface These processes allow for OCs to be absorbed from the gas phase by water, soil, plant surface and snow and become available within a range of ecosystems and habitats Arguably most detrimental to natural systems

Forest Ecosystems: Organochlorines Persist in forests due to deposition Pollutants in the air are adsorbed to leaf and needle surfaces Leaf litter transports contaminants to the soil Different soil horizons undergo alternate responses due to processes like degradation, dissolution, adsorption, and evaporation Remain in the A-horizon due to its acidic properties in pine forests

Waterways: Organochlorines Agricultural Runoff Rivers are the largest receptacles of pesticide waste and agricultural runoff Enter river systems through surface run-off from urban areas Bioavailable to the organisms living in the river Generally found in densely populated areas (target estuaries and coastal marine ecosystems) Sediments act as a sink for persistent pollutants

Effects of Organochlorines in the Lake Champlain Basin PCBs and dioxins NIOSH REL: Ca Found in sediment Low levels of PCBs throughout the lake- bioaccumulates Concentration of PCBs exceeds U.S. FDA for fish and EPA guidelines for humans Largest single source of contaminant from Georgia Pacific sludge bed in Cumberland Bay Dioxin brought to LCB from pesticide runoff (agriculture) Both PCBs and dioxin primarily transported from wind currents depositing substances from sources outside of the basin Fish advisories are a result of the elevated concentrations, promote safe fish consumption and protect human health (Lake Champlain Basin Program, 2011)

NIOSH REL: 1.5 mg/m 3

NIOSH REL: 1400 mg/m 3

NIOSH REL: Ca

Factors to consider Input duration Mass loading Predator- prey relationships Sensitivity of species Flushing time In mammals may consider gender, age, diet, health condition, reproduction status, and the season determine the effect posed on the mammal *Risk = product of many factors

Effects Filter SourceEffect Agriculture1 Urban1 WWTP1 Dams0 Roads1 Fisheries0 Marinas1 Forested Area0.5 Industrial1 Parks1 External1 Logical link between sources and stressor

Source Impact Filter* SourceImpact Agriculture2 Urban2 WWTP2 Dams0 Roads1 Fisheries0 Marinas1 Forested Area0 Industrial2 Parks0.5 External2 Logical link between the effect of the source on the stressor

Habitat Impacts Filter* HabitatImpacts Lakes/ Ponds1 Rivers/ Streams1.5 Developed Areas0.5 Forest0.5 Herbaceous0.5 Agriculture1 Wetlands1 <6ft2 >6ft1 Stressors logical link to the habitat

Uncertainty Input frequency and intensity unquantified Effect on aquatic organisms dependent on exposure severity and the physiochemical properties of the parent compound and the products it is transformed into Synergisms between chemicals within environment and amongst each other

Conclusions An abundance of toxins entering the Lake from outside the basin via deposition Primary sources of toxins include industrial and agricultural runoff and WWTP Bioaccumulative and persistent properties of these substances increase risk

Recommendations Education, Advisories Disposal Monitor sediments, find trends in changes over time Revolution

THE END WARNING: This is what happens when toxins get into the Lake (featured above, Champ taking a dip in the LCB)