Exposure Scenarios and Life Cycle Assessment Arturo A. Keller Bren School of Environmental Science & Mgmt University of California, Santa Barbara
(all flows in metric tons/yr, 2010 estimates from Future Markets, Inc.) Keller et al., J Nanoparticle Res., 2013
Comparison to other ENM Production Estimates Future Markets, Inc. a Piccino et al. (2012) Hendren et al. (2011) Gottschalk et al. (2010) Global ENM 2010 Ag 360-450 Al 2 O 3 18,500-35,000 CeO 2 7,500-10,000 CNT 2,916-3,200 US 2010 180-225 9,250-17,500 3,750-5,000 1,458-1,600 Switzerland Global b 2010 (circa 2011) 2 55 (5.5 550) 97-183 55 (55 5,500) 39-52 55 (5.5 550) 15-17 300 (55 550) Cu 22-200 11-100 0-1 Fe 33,000-16,500-173 - 220 55 42,000 21,000 (5.5 5,500) 9,200-10,400 SiO 2 82,500-95,000 TiO 2 83,500-88,000 ZnO 31,500-34,000 4,600-5,200 41,250-47,000 41,750 44,000 15,750-17,000 48-55 432-498 5,500 (55 55,000) 438 461 3,000 (550 5,500) 165-178 550 (55 550) US Switzerland c (circa 2010) (several dates) 2.8-20 [1.1][2.3][1.7] 35-700 55-1,100 [1.9][2.6][1.2] Nanoclays 7,800-38,000 [114][240][195]
Large application for many ENMs Direct human contact ENMs go into wastewater Small amount to landfill Personal Care Products
Personal Care Products Bulk of material flow is daily care products Toothpaste & others Soil Sunscreen and cosmetics are about equal in use Sunscreen WWTP WIP Water Most of these materials washed off within hours of application Cosmetics Landfill Air
Personal Care Products
ENMs in Agriculture
ENMs in Agriculture Biosolids application rates and laws vary widely Formal and informal application around the world
WWTP and Biosolids WWTP at different levels depending on infrastructure Primary => more ENMs to effluent Secondary => most ENMs to biosolids Transformation of ENMs in WWTP? Region WWTP treatment level Regional IHDI Estimated Secondary Treatment Low Estimate High Estimate Effluent Sludge Effluent Sludge Asia 0.48 13% 18% 82% 55% 45% Australia and Oceania 0.86 84% 6% 94% 30% 70% Central America and 0.45 8% 19% 81% 57% 43% Caribbean Europe 0.78 69% 8% 92% 36% 64% Middle East, North Africa, 0.45 8% 19% 81% 57% 43% and Greater Arabia North America 0.77 67% 9% 91.% 37% 63% South America 0.55 26% 15% 85% 51% 49% Sub-Saharan Africa 0.28 0% 20% 80% 60% 40% Biosolids Management Region Applied to Incinerated Landfilled Agricultural Land Asia 44% 12% 44% Australia and Oceania 66% 0% 34% Europe 52% 21% 27% Middle East, North Africa, and 0% 0% 100% Greater Arabia North America 47% 18% 34% South America 15% 0% 85% Sub-Saharan Africa 100% 0 0
Working on determining bioavailability of ENMs to different plants Understand different ENM application methods and releases ENMs in Agriculture
ENMs in WWTP and septic systems go through: Aerobic oxidation Anaerobic High S 2- High IS High NOM ENM Transformation
Modern landfills have several barriers Garbage is covered daily with soil Leachate collected & treated Operations vary widely in practice ENMs in Landfills
ENM release in landfill Most ENMs embedded in products A few applications can result in more release: PCP Food Medical
ENMs in Paints
Estuarine Mesocosm freshwater inflow + Cu NPs; Cu NP-contaminated phytoplankton; Cu NP contaminated par culate organic ma er; or Cu-NP boat-bo om paint Cu ++ dissolu on = phytoplankton = Cu NPs = Cu NPs in boat paint = par culate organic ma er seawater Inflow (with dal cycling) 40 cm deposi on feeding resuspension sediment respira on oysters excre on 60 cm Ou low + NP removal 1 m Fig. 1. Diagram of estuarine mesocosm with conceptual model for study of fate & transport of Cu NPs, and uptake, accumula on, and excre on of Cu NPs by CA na ve oysters.
Predicted Initial [ENM] in SF Bay Estimates of ENM concentrations at point of release indicate ng/l to ug/l levels to be expected
Key Points Generate more refined estimates of exposure concentrations and doses based on LCA Study F&T within mesocosms to determine bioavailability, accumulation, fate & actual exposure Understand ENM transformations in WWTP processes state of ENM before reaches environment Generate reduced form data for exposure modeling UC CEIN needs to work on commercial ENMs (coated, functionalized, composite matrices)