Edgar Hertwich Industrial Ecology Programme Norwegian University of Science and Technology

1. Who are the worst toxic polluters?Human Toxicity Potentials for Life Cycle Assessment and Screening of Manufacturing Emissions Edgar HertwichIndustrial Ecology Programme Norwegian University of Science and Technology N-7491 Trondheim, Norway Sarah Mateles, Bill Pease, Tom McKone Berkeley, California http://design.ntnu.no/lca/lab

2. Overview • SETAC Task Force on Toxicity in LCARanking & ScoringToxic equivalency potentialsSite-specific risk assessment • The Human Toxicity Potential • CalTOX and it use for Potential Dose calculations • Alternative modeling approaches • Uncertainty analysis of the potential dose • Application to the U.S. Toxics Release Inventory: • chemicals • manufacturing plants & industry sectors • Conclusions

3. SETAC Working Group on Life Cycle Impact Assessment • Different levels of sophistication: • Ranking and Scoring: Ordinal scoring of those attributes considered important (e.g. on a scale of 1-5; toxicity, bioconcentration, persistence). Cannot combined with emission amounts; not useful for LCA. • Toxic equivalency potentials: Cardinal indicators of toxicity combing toxic potency from animal tests or epidemiological studies with models of source-to-dose relationships. Models represent generic "evaluative" environments and not the situation at the release site. Population density often neglected. • Risk assessment: Site-specific modeling of exposure. Local conditions are taken into account, including characteristics of environment and population to estimate the number of people exposed over safe level or even disease incidence. Accuracy, sophistication Ease of application

4. Different methods, different evaluation principles stressor Benzene emissions insult  C6H6 concentration stress C6H6 exposure consequence leukemia HTP value lost YLL, morbidity, suffering DALY Impact chainacc. To Holdren (1980) Human health impact chain Guinée & Heijungs1993 Hofstetter(1998) Hertwich et al., J. Ind. Ecol. 4(1)

5. How do we best inform decisions? A large number of chemicals are potentially dangerous, but we know very little about them. About half of the high-production volume chemicals lack basic toxicity tests needed to determine their safety. Tradeoff between number of chemicals covered by a system and degree of detail the system can address is important. How much of the overall risk do we include in the assessment?

7. SETAC Working Group on Life Cycle Impact Assessment • General form: • Match fate&exposure indicator to toxicity indicatorHumans: release -> presented dose -> dose-response curveAquatic ecosystems: release -> concentration -> concentration-response curve • Generic indicators should be developed to account for all emissions recorded in an LCA. Investigation of site-dependent aspects should focus on those releases found to be important in the generic assessment.Concern: data on release sites; additional effort required. Indicatorscore Effect factor(toxicity) Emissions (kg) Fate factor

8. The Human Toxicity Potential • PD … Potential Dose per 1kg/d emissions of chemical i to environmental compartment j • q1* … cancer potency (for carcinogens) or inverse of RfD, RfC (for non-carcinogenic effects) • ref … reference compound (benzene, toluene) http://wimpy.arsdigita.com/public/presentation-top.adp?presentation_id=18003

9. Exposure = Sources, Transport, & Contact http://www.Scorecard.org/env-releases/def/tep_gen.html

10. Air Particles Gases Leaves Surface soil Roots Water Root-zone soil Deep soil Sediment CalTOX: Multimedia Fate and Exposure Model Uniform concentration & equilibrium in each compartment, steady state mass balance among compartments. http://eetd.lbl.gov/ied/era/

11. Exposure Histogram (TCDD)

12. Significant differences between air and surface water emissions for some chemicals due to exposure-route-dependent toxicity factors, different partitioning behavior.

13. Little correlation between toxicity and potential dose: it is important to assess both!!

14. The Toxics Release Inventory Created in response to Bhopal, the TRI contains emissions estimates for 600 different pollutants from manufacturing facilities, power plants, smelters etc. Mandatory reporting Credited with success in pollution reductions, extended. US EPA reports emissions as raw data. Environmental Defense provides data with interpretation aids: information on toxic risks, rankings, exact location etc.

15. Application of HTP: www.Scorecard.org 1998 TRI Pollution Releases Ranked by Ozone Depleting Potential Top Ranked Ozone Depleting Chemical: dichlorodifluoromethane List chemicals or facilities contributing to ozone depletion 1998 TRI Pollution Releases Ranked by Potential Human Health Risks Top Ranked Cancer Risk: arsenic (organic or inorganic compounds) List chemicals or facilities contributing to cancer risk Top Ranked Noncancer Risk: lead compounds List chemicals or facilities contributing to noncancer risk Example text, Illinois

16. Rankings of carcinogens A small number of chemicals is responsible for almost all the weighted emissions.

17. Ranking of non-carcinogens; Lbs of toluene equivalents Basis: 1998

18. Toxic Pollution by Industry Sector

19. The Dirty Dozen

20. Conclusions • The Human Toxicity Potential (HTP) is a powerful tool for comparing toxic emissions from different facilities and life-cycle stages. • HTP is based on state-of-the-art chemical fate and exposure modeling and risk assessment values (toxicity indicators) used in chemical regulation • HTP does not take into account the number of people exposed or differences in the local environment • With Environmental Defense's Scorecard project, HTP contributed to improving public information about environmental risks. • Smelting, mining, electrical power plants, and chemical industry are the most polluting industrial sectors (by far). Renewed effort in addressing these emissions is required. • TRI does not yet include PM2.5, NOx, SO2.