Environmental Health Issues in Solid Waste Management Alan Eschenroeder, Ph.D. and Katherine von Stackelberg, S.M. Harvard School of Public Health 18 November 2002

A Four Step Policy Hierarchy in Municipal Waste Management

Analyses Compare Landfill with Combustion Two size scales; Two technology scenarios Microscale: Local human health impacts Macroscale: Global climate change impacts Current regulation defines technology level. Pollution prevention determines technology level.

Waste Stream for Both Facilities Source reduction and recycling are constant tpd of MSW stays level through 30 years. Both have a post-closure period of 70 years.

Health Risk Methodology for Both Facilities Identify hazards, and characterize emissions. Assess dose-response relationships. Assess human exposures through various routes. Characterize health risks. Follow EPA protocol for analyzing risk.

Contemporary Landfill Scenarios: Present Regulation: Subtitle D - “ dry tomb ” Pollution Prevention: Leachate recycling - “ wet cell ”

Contemporary Combustor Scenarios: Present regulation: Max. Available Control Tech. Pollution Prevention: Energy Answers System

The risk analysis includes many pathways.

The landfill generates gas for a long time.

How do health risks compare? landfill versus combustion assuming equal recycling

Most of the landfill risk is in groundwater

Compare climate change impacts Calculate GHG emissions over a 100 year period Model CO 2 atmospheric response from IPCC data CH 4, N 2 O, and CFC removal follow IPCC kinetics Obtain radiative forcing histories for both facilities

Cases Studied in Climate Change Analysis Case 1: Landfill (LF) with no gas collection; neither landfill or resource recovery (RR) is credited for displacing fossil fuel power plants. Case 2: LF collects its gas; both LF and RR receive fossil fuel emission displacement credits. Case 3: Identical to Case 1 except both LF and RR receive biogenic carbon discounts. Case 4: Identical to Case 2 except both LF and RR receive biogenic carbon discounts.

How do IPCC biogenic discounts work? Materials of recent biogenic origin are credited by assuming that the CO 2 emitted cancels out that taken up in the plant of origin Bioreactive wastes include paper, paperboard, wood products natural fiber, food waste and yard trimmings. Materials of not-so-recent biogenic origin are not credited. Nonreactive materials include fossil fuels, plastics, synthetic fibers, rubber and leather [Aren’t cows and rubber trees recent enough?].

Climate Change Comparison: Case 1 without energy credits LF/RR=115

Climate Change Comparison: Case 2 with energy credits LF/RR=45

Climate Change for Four Cases in terms of watt-years/ square kilometer

Concluding Observations Health concerns drive opposition to combustion. Health risk usually is not considered for landfills. Combustion wins out over landfills on health risk especially if groundwater quality is a factor. The climate change impacts of combustors are significantly less than those caused by landfills. Climate change issues are still being debated.

Environmental Health Research Needs Improved communication of relative risks and social tradeoffs among alternative outcomes Modeling and risk comparisons for fine particle health impacts of waste management facilities Gas / particle partitioning of dioxins in plume and ambient environments Reexamination of global warming potentials under scenarios of continuous rather than puff emissions

Carbon Balance on Landfilled Waste

Carbon Sequestration by Forest Products

Geochemical Carbon Cycle Time Scales