SCCWRP #1373
`
`Contents lists available at ScienceDirect
`Science of the Total Environment
`
`journal homepage: www.elsevier.com/locate/scitotenv
`
`Review
`Where the rubber meets the road: Emerging environmental impacts of tire
`wear particles and their chemical cocktails
`Paul M. Mayer a,*, Kelly D. Moran b, Ezra L. Miller b, Susanne M. Brander c, Stacey Harper d,
`Manuel Garcia-Jaramillo e, Victor Carrasco-Navarro f, Kay T. Ho g, Robert M. Burgess g, Leah
`M. Thornton Hampton h, Elise F. Granek i, Margaret McCauley j, Jenifer K. McIntyre k,
`Edward P. Kolodziej l, Ximin Hu m, Antony J. Williams n, Barbara A. Beckingham o,
`Miranda E. Jackson e, Rhea D. Sanders-Smith p, Chloe L. Fender e, George A. King q,
`Michael Bollman a, Sujay S. Kaushal r, Brittany E. Cunningham s, Sara J. Hutton v,
`Jackelyn Lang t, Heather V. Goss u, Samreen Siddiqui c, Rebecca Sutton b, Diana Lin b,
`Miguel Mendez b
`a US Environmental Protection Agency, Office of Research and Development, Center for Public Health and Environmental Assessment, Pacific Ecological Systems Division,
`Corvallis, OR 97333, United States of America
`b San Francisco Estuary Institute, 4911 Central Ave, Richmond, CA 94804, United States of America
`c Department of Fisheries, Wildlife, and Conservation Sciences, Coastal Oregon Marine Experiment Station, Oregon State University, Corvallis, OR 97331, United States of
`America
`d Department of Environmental and Molecular Toxicology, School of Chemical, Biological and Environmental Engineering, Oregon State University, Corvallis, OR 97333,
`United States of America
`e Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, OR 97331, United States of America
`f Department of Environmental and Biological Sciences, University of Eastern Finland, Kuopio Campus, Yliopistonranta 1 E, 70211 Kuopio, Finland
`g US Environmental Protection Agency, ORD/CEMM Atlantic Coastal Environmental Sciences Division, Narragansett, RI 02882, United States of America
`h Southern California Coastal Water Research Project, 3535 Harbor Blvd, Suite 110, Costa Mesa, CA 92626, United States of America
`i Environmental Science & Management, Portland State University, Portland, OR 97201, United States of America
`j US Environmental Protection Agency, Region 10, Seattle, WA 98101, United States of America
`k School of the Environment, Washington State University, Puyallup Research & Extension Center, Washington Stormwater Center, 2606 W Pioneer Ave, Puyallup, WA
`98371, United States of America
`l Interdisciplinary Arts and Sciences (UW Tacoma), Civil and Environmental Engineering (UW Seattle), Center for Urban Waters, University of Washington, Tacoma, WA
`98402, United States of America
`m Civil and Environmental Engineering (UW Seattle), University of Washington, Seattle, WA 98195, United States of America
`n US Environmental Protection Agency, Center for Computational Toxicology and Exposure, Chemical Characterization and Exposure Division, Computational Chemistry
`& Cheminformatics Branch, 109 T.W. Alexander Drive, Research Triangle Park, NC 27711, United States of America
`o Department of Geology & Environmental Geosciences, College of Charleston, Charleston, SC, 66 George Street Charleston, SC 29424, United States of America
`p Washington State Department of Ecology, 300 Desmond Drive SE, Lacey, WA 98503, United States of America
`q CSS, Inc., 200 SW 35th St, Corvallis, OR 97333, United States of America
`r Department of Geology and Earth System Science Interdisciplinary Center, University of Maryland, College Park, MD 20740, United States of America
`s Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, OR 97333, United States of America
`t Department of Anatomy, Physiology, and Cell Biology, Department of Medicine and Epidemiology and the Karen C. Drayer Wildlife Health Center, University of
`California, Davis School of Veterinary Medicine, Davis, CA 95616, United States of America
`u US Environmental Protection Agency, Office of Water, Office of Wastewater Management, Washington, DC 20004, United States of America
`v GSI Environmental, Inc., Olympia, Washington 98502, USA
`
`* Corresponding author.
`E-mail addresses: mayer.paul@epa.gov (P.M. Mayer), kellym@sfei.org (K.D. Moran), ezram@sfei.org (E.L. Miller), susanne.brander@oregonstate.edu
`(S.M. Brander), stacey.harper@oregonstate.edu (S. Harper), manuel.g.jaramillo@oregonstate.edu (M. Garcia-Jaramillo), victor.carrasco.navarro@uef.fi
`(V. Carrasco-Navarro), Ho.Kay@epa.gov (K.T. Ho), Burgess.robert@epa.gov (R.M. Burgess), leahth@sccwrp.org (L.M. Thornton Hampton), graneke@pdx.edu
`(E.F. Granek), mccauley.margaret@epa.gov (M. McCauley), jen.mcintyre@wsu.edu (J.K. McIntyre), koloj@uw.edu (E.P. Kolodziej), xhu66@uw.edu (X. Hu),
`Williams.antony@epa.gov (A.J. Williams), beckinghamba@cofc.edu (B.A. Beckingham), miranda.jackson@oregonstate.edu (M.E. Jackson), Rhea.smith@ecy.wa.
`gov (R.D. Sanders-Smith), chloe.fender@oregonstate.edu (C.L. Fender), king.george@epa.gov (G.A. King), bollman.mike@epa.gov (M. Bollman), skaushal@umd.
`edu (S.S. Kaushal), cunningb@oregonstate.edu (B.E. Cunningham), SJHutton@gsi-net.com (S.J. Hutton), jblang@ucdavis.edu (J. Lang), Goss.heather@epa.gov
`(H.V. Goss), samreen.siddiqui@oregonstate.edu (S. Siddiqui), rebeccas@sfei.org (R. Sutton), diana@sfei.org (D. Lin), miguelm@sfei.org (M. Mendez).
`https://doi.org/10.1016/j.scitotenv.2024.171153
`
`Science of the Total Environment 927 (2024) 171153
`
`Available online 7 March 2024
`0048-9697/Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
`
`Exhibit 1132
`Bazooka v. Nuhn - IPR2024-00098
`Page 1 of 28
`
`

`

`P.M. Mayer et al.
`
`H I G H L I G H T S
`• Billions of tires are produced each year
`and hundreds of millions of tires become
`waste.
`• Tires are a complex source of pollutants
`including whole tires, particles, com-
`pounds, and chemicals.
`• As they wear, tires emit pollutants via
`atmospheric, aquatic, and terrestrial
`pathways.
`• Tire wear pollutants represent an envi-
`ronmental and human health risk.
`• Comprehensive clean-up solutions are
`needed to reduce the risk of tire wear
`pollutants.
`
`A R T I C L E I N F O
`
`Editor: Dimitra A Lambropoulou
`
`Keywords:
`Persistent pollutants
`Emerging contaminants
`Microplastics
`Tire wear particles
`6PPD-quinone
`
`G R A P H I C A L A B S T R A C T
`
`A B S T R A C T
`About 3 billion new tires are produced each year and about 800 million tires become waste annually. Global
`dependence upon tires produced from natural rubber and petroleum-based compounds represents a persistent
`and complex environmental problem with only partial and often-times, ineffective solutions. Tire emissions may
`be in the form of whole tires, tire particles, and chemical compounds, each of which is transported through
`various atmospheric, terrestrial, and aquatic routes in the natural and built environments. Production and use of
`tires generates multiple heavy metals, plastics, PAH's, and other compounds that can be toxic alone or as
`chemical cocktails. Used tires require storage space, are energy intensive to recycle, and generally have few post-
`wear uses that are not also potential sources of pollutants (e.g., crumb rubber, pavements, burning). Tire particles
`emitted during use are a major component of microplastics in urban runoff and a source of unique and highly
`potent toxic substances. Thus, tires represent a ubiquitous and complex pollutant that requires a comprehensive
`examination to develop effective management and remediation. We approach the issue of tire pollution holis-
`tically by examining the life cycle of tires across production, emissions, recycling, and disposal. In this paper, we
`synthesize recent research and data about the environmental and human health risks associated with the pro-
`duction, use, and disposal of tires and discuss gaps in our knowledge about fate and transport, as well as the
`toxicology of tire particles and chemical leachates. We examine potential management and remediation ap-
`proaches for addressing exposure risks across the life cycle of tires. We consider tires as pollutants across three
`levels: tires in their whole state, as particulates, and as a mixture of chemical cocktails. Finally, we discuss in-
`formation gaps in our understanding of tires as a pollutant and outline key questions to improve our knowledge
`and ability to manage and remediate tire pollution.
`
`1. Introduction
`Global dependence on tires produced from petroleum-based com-
`pounds, synthetic materials, heavy metals, and added chemicals, rep-
`resents a persistent and complex environmental problem with only
`partial, and often-times ineffective, solutions. Used tires require storage
`space, are energy intensive to recycle, and end-of-life uses for tires (e.g.,
`crumb rubber, pavements, combusted tires) generally continue to
`release pollutants as particles or leached chemicals, or both. Tires are a
`significant source of highly mobile, persistent microplastics (Moran
`et al., 2021; Brander et al., 2021) that are a major component of pol-
`lutants in urban stormwater runoff (Wik and Dave, 2009). Furthermore,
`recent research has demonstrated that tires are a source of previously
`unrecognized chemicals, some are highly toxic to aquatic organisms,
`and many of which are currently unknown or poorly described (Tian
`et al., 2021a; Siddiqui et al., 2022; Cunningham et al., 2022). Production
`and use of tires generate a suite of heavy metals and other contaminants
`that can be toxic alone or as chemical cocktails, which represent com-
`binations of elements novel to the Anthropocene (sensu Kaushal et al.,
`2020). Given that roads are ubiquitous in developed nations (Ibisch
`et al., 2016), cover extensive areas in urban ecosystems (Elmore and
`Kaushal, 2008), and that road construction and traffic are increasing
`worldwide (Meijer et al., 2018), the impacts of tires are vast and are
`
`expected to increase globally. Roads can represent hot spots of tire
`pollutants and effective pathways of pollutants to aquatic, terrestrial,
`atmospheric, and groundwater resources (Cooper et al., 2014; Sommer
`et al., 2018; Uliasz-Misiak et al., 2022).
`Here we synthesize recent research and data about the environ-
`mental and human health risks associated with tire production, use, and
`disposal. We discuss gaps in our knowledge about fate and transport, as
`well as the toxicology of tire particles and leachates. We examine po-
`tential management and remediation approaches for addressing expo-
`sure risks across the life cycle of tires and associated contaminants. We
`consider tires as pollutants across three levels: whole tires, tire wear
`particles, and as a mixture of chemical constituents. Finally, we outline
`key questions to expand our knowledge and ability to manage and
`remediate pollution from tires.
`2. The composition of tires
`Tires are constructed of multiple, highly engineered components,
`including tread, belts, inner liners, and sidewall, each designed to meet
`performance characteristics that together create durable, strong, reli-
`able, and safe tires (USTMA, 2018) which are the same properties that
`ensure the persistence of tire particles and tire materials in the envi-
`ronment. Tires contain myriad materials and chemicals, many of which
`
`Science of the Total Environment 927 (2024) 171153
`
`2
`
`Exhibit 1132
`Bazooka v. Nuhn - IPR2024-00098
`Page 2 of 28
`
`

`

`P.M. Mayer et al.
`are proprietary (Tian et al., 2021b). Tires typically use metal mesh or
`Manufacturing tires requires copious water and electricity and produces
`textiles for structure and rubber for all other components. Tire rubber
`nitrogen oxides (NOx), benzene, and PAHs (Dong et al., 2021). Each tire
`consists of complex proprietary formulations that vary among brands,
`life cycle stage has multiple impacts on climate and acidification from
`energy use and production of CO2, ozone depletion, photochemical
`tire types, and tire components (Hüffer et al., 2019; Kreider et al., 2010;
`oxidation, and eutrophication from NOx production and use of PO43(cid:0)
`in
`Selbes et al., 2015; Wagner et al., 2018; Chibwe et al., 2022). In general,
`manufacturing (Dong et al., 2021; Sun et al., 2016).
`tire rubber consists of synthetic and/or natural rubber (40–60 %), fillers
`and reinforcing agents like carbon black and silica (20–25 %), process or
`extender oils (12–15 %), vulcanization agents like Zn and thiazoles (1–2
`%), and other additives such as preservatives and processing aids (5–10
`%) (Wagner et al., 2018). Tires contain approximately 50:50 ratio of
`natural to synthetic rubber; passenger car tires contain more synthetic
`rubber, while truck tires more natural rubber, and heavy-duty vehicles
`tires contain little or no synthetic rubber (Grammelis et al., 2021). Tires
`contain thousands of chemicals, including those deliberately added,
`such as N-(1,3-dimethylbutyl)-N′-phenyl-p-phenylenediamine (6PPD,
`DTXSID9025114; CAS 793–24-8), contaminants in manufacturing
`feedstocks, such as polycyclic aromatic hydrocarbons (PAHs), and
`weathering or transformation products as tires age (Tian et al., 2021b;
`European Tyre and Rubber Manufacturer’s Association, 2021; Kovo-
`chich et al., 2021). As a result, there is no standard chemical composi-
`tion of tire wear particles. This creates challenges for monitoring and
`characterizing tire particles and tire-derived chemicals in environmental
`samples, for estimating tire microplastics fate, and for conducting eco-
`toxicology impact assessments. Determining the complete and quanti-
`tative chemical composition of tire rubber remains a critical research
`need.
`3. Environmental and health impacts along the life cycle of tires
`The life cycle of a tire can be characterized by stages including a) raw
`materials and production of the whole tire, b) transportation of the tire
`to a destination, c) use on a vehicle, and d) end of life management
`through downcycling into non-tire products or disposal (Dong et al.,
`2021; Trudsø et al., 2022). Here, we examine these stages as a contin-
`uum along the life cycle of a tire (Fig. 1) where tires and their compo-
`nents are produced and used. In the process, energy and resources are
`consumed while particles and elements are emitted and transported
`through the environment across various pathways (Trudsø et al., 2022).
`At points along those pathways, there are potential mitigation ap-
`proaches to reduce environmental impacts including reuse or disposal,
`and, in some cases, recycling into new tires and tire related products.
`
`3.1. Environmental and health impacts from the production of tires
`Global demand for automobile tires is large and growing. In 2019
`alone, 3 billion tires were produced globally (Ruwona et al., 2019; Dong
`et al., 2021), an amount that, if stacked on top of one another, would
`reach ca. 675,000 km, nearly twice the distance to the moon. Recent tire
`production in the EU is about 335 million annually (Torretta et al.,
`2015), while tire production was about 300 million in the US (USTM,
`2022) and about 800 million in China (Dong et al., 2021). Tire pro-
`duction begins with acquisition of natural rubber for the tread, textiles
`and steel for the cord and belts, and chemicals such as carbon black,
`silicon dioxide, and clay (Dong et al., 2021). A significant environmental
`impact of tire production is from the cultivation of natural rubber which
`involves clearing native, diverse forests for growing monocultures of
`rubber trees. This type of agriculture is an especially important cause of
`deforestation in Asia and Africa (Pendrill et al., 2022). High resolution
`maps of southeast Asia show that rubber tree cultivation accounted for
`at least 4 million ha of deforestation since 1993, 2 million ha of which
`was lost since 2000, including 1 million ha of rubber plantations that
`have been established in high biodiversity areas (Wang et al., 2023).
`Combining tire components during production emits carcinogens
`and radioactive compounds (e.g. radon-222 and carbon-14), contributes
`to stratospheric ozone depletion, and requires massive consumption of
`water and electricity, and land in the form of extraction of minerals and
`fossil fuels, and water (Piotrowska et al., 2019). Combined, the various
`chemical components and the particles create chemical cocktails (sensu
`Kaushal et al., 2018, Kaushal et al., 2020, Kaushal et al., 2022) of heavy
`metals (e.g., Zn), natural and synthetic rubber and plastics, hydrocar-
`bons (e.g., PAHs), and traces of other chemicals (e.g., 6PPD) that can
`have negative effects on human health and the environment.
`Manufacturing a single tire produces an estimated 243 g particulate
`matter to the air, 0.19 g NH4+ and 0.69 g suspended solids to the water
`(Sun et al., 2016). On average, 6 MJ of electrical energy, 45 L of water,
`and 0.02 kg of dissolvent are needed to manufacture one tire while
`
`Fig. 1. Life cycle of tires
`
`Science of the Total Environment 927 (2024) 171153
`
`3
`
`Exhibit 1132
`Bazooka v. Nuhn - IPR2024-00098
`Page 3 of 28
`
`

`

`P.M. Mayer et al.
`yielding 0.5 kg of waste (Piotrowska et al., 2019). Extrapolating from an
`million tires (USTMA, 2020). The global annual production of waste
`estimated 3 billion tires produced annually, tire manufacture may pro-
`tires is estimated to reach 1.2 billion tons by the 2030s (Liu et al., 2020).
`duce as much as 729 million kg particulate matter, 570,000 kg NH4+, and
`Others estimate that, globally, 1.5 billion tires are discarded annually
`over 2 million kg suspended solids annually, while as much as 104
`currently with an expected to increase to 5 billion tires by 2030
`billion MJ energy may be consumed along with over 70 billion liters of
`(Grammelis et al., 2021). Generally, waste tires remain in the region of
`water though, water and energy consumption could be reduced through
`their production. For example, only 3.1 % and 5.7 % of waste tires are
`existing technologies, including high-pressure steam to shorten vulca-
`exported from the US (USTMA, 2020) and the EU (Sienkiewicz et al.,
`nization time and recovery of waste steam (Sun et al., 2016). Using the
`2012), respectively. Waste tires are often recycled into various products,
`Intergovernmental Panel on Climate Change (IPCC) methodology, each
`including outdoor products with high potential to disperse tire particles
`tire requires over 333,000 kg CO2 Eq during production while 2116 kg
`or tire-derived chemicals into the environment (Dabic-Miletic et al.,
`of CO2 Eq are recovered by recycling a tire (Piotrowska et al., 2019).
`2021). For example, the majority of waste tire use in California, USA
`Some tire manufacturers are striving to reduce their factory carbon
`includes burning for fuel, crumb rubber production, and integration in
`footprint and/or exploring new tire designs with longer lifespan or
`civil engineering applications (Table 1). Worldwide, the fate of tires is
`which could be retread like industrial tires, thereby saving significantly
`similar with most going into energy production or recycled (Table 2).
`on the amounts of materials required for production (https://www.
`Tires are often downcycled into microplastic-containing products like
`motortrend.com/features/future-tire-technology/?id=applenews).
`tire crumb and tire buffings. Used tire processors separate tire rubber
`from tire structural components (e.g., steel belts) to produce various
`sized tire rubber pieces (Valente and Sibai, 2019) classified as buffings,
`3.2. Environmental and health impacts from the use of tires
`ground, crumb, or aggregate, some of which contain or are entirely
`composed of microplastics. Products created from used tires include
`Significant ecosystem impacts are from tire emissions of carbon di-
`retreaded tires, tire-derived fuel, artificial turf infill, rubberized asphalt,
`oxide and sulfur oxides or nitrogen oxides, which are greatest during the
`shock absorption applications, landscaping mulch, playground and
`use stage of the life cycle and a function of fuel use of the vehicle
`recreational areas, rubber-containing pavement seal coats, rubberized
`(Piotrowska et al., 2019). Tire wear during use results in tire wear
`building and floor materials, railroad ties, and doormats (Dabic-Miletic
`particle emissions into the environment. Vehicle tire wear produces an
`et al., 2021). There are 12,000–13,000 synthetic turf fields in the US
`estimated 1.2–6.7 kg of particles, or about 10–16 % of the weight of the
`with 1200–1500 new installations annually (USEPA, 2019). Wear of turf
`tire, over the lifetime of the tire (Sun et al., 2016; USTMA, 2021). Tire
`fields, tracks, and other recreational areas where recycled tire crumb
`wear and evolution of tire wear products may be exacerbated by the
`rubber is used can release tire microplastics into the environment (Wang
`heavier weight and increased acceleration and torque produced by EVs
`et al., 2021).
`(Zhao et al., 2019). Tire microplastics from synthetic rubber tires are a
`major contributor of microplastic pollution to the environment (Kole
`4. Fate and transport
`et al., 2017; Sieber et al., 2020; Siegfried et al., 2017). Measurable and
`sometimes significant amounts of tire particles have been collected in
`4.1. Cycling of tire particles in the environment
`air, aquatic environments, and organisms (Baensch-Baltruschat et al.,
`2020; Leads and Weinstein, 2019; Siegfried et al., 2017; Tian et al.,
`Studies of the fate and transport of tire microplastics and associated
`2017; Werbowski et al., 2021; Wik and Dave, 2009). For example, un-
`contaminants has been limited. A handful of studies have helped to
`treated stormwater runoff samples collected from San Francisco Bay
`characterize tire microplastics and affiliated leachate in the environ-
`watersheds contained up to 15.9 tire particles/L, almost 50 % of all
`ment associated with urban runoff (Werbowski et al., 2021; Johannes-
`microparticles in these samples (Sutton et al., 2019; Werbowski et al.,
`sen et al., 2021; Kl¨ockner et al., 2020; Kl¨ockner et al., 2021; Peter et al.,
`2021). Globally, tires may be one of the top sources of microplastics to
`2018; Peter et al., 2020; Tian et al., 2021b). Data from Europe show that
`the environment (Boucher and Friot, 2017; Kole et al., 2017; Sieber
`most of the mass of tire microplastics is deposited near roadsides, but
`et al., 2020), with a pollutant mass exceeding the total environmental
`that water and atmospheric pathways can move particles significantly
`emissions of other pollutant classes like pharmaceuticals and pesticides
`farther (Baensch-Baltruschat et al., 2021; Evangeliou et al., 2020; Sieber
`(Wagner et al., 2018).
`et al., 2020; Sommer et al., 2018; Verschoor et al., 2016). Moran et al.
`Tire emissions generally relate to vehicle weight, tire size, and dis-
`(2021) conceptualized the sources and pathways of rubber particles to
`tance traveled, with larger heavier vehicles (trucks) emitting more than
`urban stormwater (Fig. 2).
`small light ones. Higher traffic speeds result in increased generation of
`tire particles (Wang, 2017; Pohrt, 2019; Kwak et al., 2013; Foitzik et al.,
`2018). Particle generation from any specific vehicle or in specific
`roadway segments can vary depending on driving speed or style (e.g.,
`urban stop/go vs. highway), road surface condition, type of contact
`(rolling vs. slipping) and temperature (Alexandrova et al., 2007; Knight
`et al., 2020; Kole et al., 2017). Based on relatively limited data, country-
`specific tire particle generation across size classes 10 nm to 1000 μm has
`been estimated to be as low as 0.23 kg/yr/capita in India to as high as
`5.5 kg/yr/capita in the US due to its longer per-capita annual vehicle
`travel distances (Mennekes and Nowack, 2022; Baensch-Baltruschat
`et al., 2020; Councell et al., 2004; Wagner et al., 2018; Kole et al., 2017).
`Thus, approximately 1.7 million tons of tire wear particles are produced
`annually in the US based on 2021 population size. Where automobile
`and truck traffic are higher, production of particles may be significantly
`greater. Based on empirical and extrapolated data synthesized from
`Europe, Japan, China, Australia, Brazil, India, and USA annual global
`tire wear emissions, across size classes 10 nm (cid:0) 1000 μm, were estimated
`to be nearly 6 million tons (Baensch-Baltruschat et al., 2020).
`Annually, about 800 million tires become waste material worldwide
`(Tsang, 2012). In the US, scrap tire generation in 2019 was about 260
`
`Table 1
`California waste tire use summary 2018*. Source: CalRecycle, 2019. *Includes
`material imported from out of state. Reprinted from Moran et al. (2021).
`Use
`Examples
`Quantity
`(Metric
`Tons)
`130,000
`82,000
`98,000
`82,000
`81,000
`
`Combustion
`(export)
`Combustion
`Landfill
`Reuse on vehicles
`Crumb/ground
`rubber
`
`Civil engineering
`applications
`Other recycling
`
`Burned at non-California facilities
`“Tire-derived fuel” burned at four California
`facilities
`Disposal, alternative daily cover
`Used tires and retreads
`Rubberized asphalt pavement (60–67 %)
`Artificial turf infill (11–14 %)
`Mulch and ground covers (3–5 %)
`Molded & extruded products (19–20 %)
`Landfill structures, construction fill, vibration
`damping, and stormwater capture and
`treatment systems
`Unspecified
`
`4600
`
`3100
`
`Science of the Total Environment 927 (2024) 171153
`
`4
`
`Exhibit 1132
`Bazooka v. Nuhn - IPR2024-00098
`Page 4 of 28
`
`

`

`Table 2
`Fate of End of Life (Scrap) Tires in the United States and Europe in 2019. 76 % of
`scrap tires in the US are utilized in some fashion (not disposed of) and 95 % in
`the EU27 + NO+CH + RS + TR + UK. Sources: 1USTMA 2019. U.S. Scrap Tire
`Management Summary. U.S. Tire Manufacturer Association. Washington, D.C.
`20005. 2 European Tyre and Rubber Manufacturing Association (ETRMA). Press
`Release: In Europe 95 % of all End of Life Tyres were collected and treated in
`2019.
`https://www.etrma.org/news/in-europe-94-of-all-end-of-life-tyres-we
`re-collected-and-treated-in-2019/
`Europe2
`Disposition
`United
`States1
`EU27 +
`(thousands of
`NO+CH + RS
`metric tons)
`+ TR + UK
`112.95 (3.2
`%)
`
`Civil Engineering
`and Similar
`Uses
`
`333.20
`(8.2 %)
`
`Recycling
`
`987.92
`(24.4 %)
`
`1841.20
`(51.8 %)
`
`Notes
`
`USA: includes Steel,
`Reclamation Projects,
`Agricultural, Baled Tires to
`Market and Punched
`Stamped. EU: includes public
`works and backfilling
`USTMA does not use
`Recycling category. Ground
`Rubber included in total here.
`For EU, includes granulation
`and additions to cement
`manufacturing.
`EU: Cement kilns 75 % and 25
`% Urban Heating and power
`plants
`
`1428.82
`(40.2 %)
`
`Energy
`Production
`Exported
`Other
`Land disposed
`Unknown/stocks
`Total
`
`1493.98
`(36.9 %)
`125.19
`(3.1 %)
`119.64
`(3.0 %)
`616.89
`(15.2 %)
`372.84
`(9.2 %)
`4049.67
`
`165.16 (4.6
`%)
`3555.61
`
`Totals are from Source Tables
`
`P.M. Mayer et al.
`indicate that most tire wear particle volume (and therefore mass) is in
`the coarse fraction (particles >50 μm), which deposit quickly from the
`source, landing on or close to pavements. While no studies show the full
`range of particle sizes, most tire wear particles are fine and ultrafine
`(Alves et al., 2020; Cadle and Williams, 1978; Fauser et al., 2002;
`Kreider et al., 2010). The smaller coarse and larger fine particles (be-
`tween 1 μm and 10 μm), can be entrained into the atmosphere through
`mechanical processes, such as from the intense turbulence generated by
`high speed vehicle traffic (Brahney et al., 2021) and have atmospheric
`residence times of 8 days (<10 μm; “PM10”) to 28 days (<2.5 μm;
`“PM2.5”) (Evangeliou et al., 2020).
`Fine (<10 μm) and ultrafine (<2.5 μm) tire particles comprise only a
`small fraction of the total mass of tire wear particles. However, they
`compose a large fraction of the total number of emitted particles, and
`their surface area might make them important vectors for tire chemical
`transport beyond the immediate roadside area. This is particularly true
`for smaller organisms and/or sensitive life stages. Due to limited data
`addressing tire particles across the full particle size distribution and the
`lack of surface area measurements for each size fraction, the role and
`importance of air deposition in tire particle and chemical transport
`within and between watersheds remains largely unknown (Moran et al.,
`2021).
`Ultimately, tire wear particles are incorporated into soils and sur-
`faces, washed off outdoor surfaces with runoff (Field et al., 2000;
`American Society of Civil Engineers, 1998), or washed out of the air by
`rainfall or snow. Particle wash-off from impervious surfaces (e.g., streets,
`sidewalks, roofs) is far more efficient than from permeable surfaces (e.g.,
`lawns, gardens, agricultural fields) (Field et al., 2000; Pitt et al., 2008).
`Estimates of the portion of tire wear debris that is washed off of urban
`outdoor surfaces into urban runoff are highly variable and likely a
`function of many system and condition specific variables; e.g., 15–50 %,
`Wagner et al., 2018; 35 %, Blok, 2005; 80 %, Kennedy et al., 2002).
`Modern urban and roadway drainage systems direct stormwater
`runoff directly (or indirectly via storm drains), untreated, into local
`water bodies. While tire particles may be temporarily retained in low
`points in stormwater collection systems under low flow conditions due
`to their density, turbulent flows during larger storm events will likely
`mobilize these particles and carry them into surface waters (Hoellein
`et al., 2019).
`Tire particles may be washed by stormwater runoff into wastewater
`treatment systems. There are no current data on fate or volumes of tire
`particles specifically in wastewater treatment plants; however, data
`suggest that a high percentage of other microplastic particles transfer
`from the water into sewage sludge (Baensch-Baltruschat et al., 2021).
`Even with high removal rates, significant annual loadings of tire and
`road wear particles have been estimated in treated wastewater effluent
`in the UK (Parker-Jurd et al., 2021). Sewage sludge is typically incin-
`erated, disposed of in landfills or spread on agricultural fields (Duis and
`Coors, 2016) where tire particles may remain in the soil or be mobilized
`and distributed by wind or by surface runoff to the aquatic environment
`(Duis and Coors, 2016; Baensch-Baltruschat et al., 2021).
`Air transport and runoff may carry tire particles and associated
`chemicals into surface water drinking water sources (Johannessen and
`Metcalfe, 2022; Zhang et al., 2023). Drinking water treatment plants
`draw water from surface water, groundwater, and/or seawater, all of
`which may contain microplastics including tire particles (Collivignarelli
`et al., 2018). Drinking water treatment typically starts with screening
`and grit removal, followed by addition of alum to the raw water for
`coagulation, flocculation, and settling in tanks. Drinking water treat-
`ment plants are effective at removing small particles including 70–83 %
`of microplastics (<100 μm) with treatment by coagulation and mem-
`brane filtration showing high effectiveness (Nikiema and Asiedu, 2022;
`Pivokonsky et al., 2018). However, the level and types of drinking water
`treatment varies widely and effectiveness of drinking water treatment
`technologies to remove tire particles specifically is unknown.
`Particle density affects particle transport. While tire rubber has a
`
`Abrasion by pavement during vehicle use creates small tire wear
`particles. After their initial release to the air, tire wear particles may
`travel short (1–10 m) to long (km) distances prior to deposi