Plastic Pellets in
the Aquatic Environment:
Sources and Recommendations
United States Environmental Protection Agency Office of Water (WH-556F) EPA 842/B-92/010 Dec92
Tables
[Table of contents | Executive Summary | Sections 1 · 2 · 3 · 4 · 5 · Glossary | Tables | References ]
Table 1. Annual U.S. Resin Sales.
Annual Resin % Sales(a) . 1989 1990 Thermoplastic Resins Low-density polyethylene (LDPE) 18.5 19.3 Polyvinylchloride (PVC) and copolymers 14.7 15.1 High-density polyethylene (HDPE) 14.0 13.8 Polypropylene (PP) and copolymers 12.5 13.2 Polystyrene (PS) 8.8 8.4 Thermoplastic polyester polyethylene terephthalate(PET) 3.6(b) 3.8(b) Thermoplastic polyester polybutylene terephthalate(PBT) ——— ——— Acrylonitrile/butadiene/styrene(ABS) 2.1 2.0 Other styrenics 2.0 1.8 Other vinyls 1.5 1.5 Polyamide (nylon) 1.0 0.9 Acrylic 1.3 1.2 Thermoplastic elastomers 0.9 0.9 Polycarbonate 1.1 1.0 Polyphenylene-based alloys 0.3 0.3 Styrene/acrylonitrile (SAN) 0.2 0.2 Polyacetyl 0.2 0.2 Cellulosics 0.2 0.1 Thermoset Resins Phenolics 4.9 4.6 Polyurethane 5.5 5.3 Urea and melamine 2.4 2.3 Polyester, unsaturated 2.3 2.0 Epoxy 0.8 0.8 Alkyd 0.6 0.5 Others 0.5 0.5source: http://www.epa.gov/owowwtr1/OCPD/PLASTIC/1-sale.html 14apr03
Table 2. Characteristics and Uses of Plastics
Additives.
[Adapted from EPA, 1990a]
Additive Conc. Typical Polymers Examples or Types of Additives (lb) (a) Using Additive . Antimicrobials - Increase resistance to microorganisms Low (<1) Polyurethane, PVC, PE Oxybisphenoxarsine; isothiazalone Antioxidants - Prevent deterioration during processing and Low (<1) Impact styrene, ABS, polyolefins long-term use Phenolics; amines; phosphates; thioesters Antistatic agents - Control static buildup during processing Low (<1) PVC, polyurethane, polyolefins and in final product Amine salts; phosphoric acid esters; polyethers Blowing agents - Add porosity to produce foamed plastics Moderate (1-5) Polyurethane, PVC, PP, PS, ABS Azobisformamide; chlorofluorocarbons; pentane Catalysts and curing agents - Facilitate polymerization Low (<1) Polyurethane and curing of resins Numerous Colorants - Enhance appearance of consumer products Low (1-2) Numerous Organic and inorganic pigments and dyes Fillers - Enhance physical properties (e.g., hardness) High (10-50) Unsaturated polyester, PVC and reduce production costs Minerals (e.g., calcium carbonate wood flours) High (10-20) Various Flame retardants - Reduce combustibility Aluminum trihydrate; antimony oxide; halogenated hydrocarbons; organophosphates Free-radical initiators - Assist in polymerization and (<1) LDPE, PS, PVC, acrylics, PE curing processes Peroxides; azo compounds Low Heat stabilizers - Improve heat resistance or prevent Moderate (1-5) PVC degradation by heat Organotin mercaptides; lead compounds; barium, cadmium, and zinc soaps Impact modifiers - Improve strength and impact resistance High (10-20) Polyolefins, PVC, Methacrylate butadiene styrene; chlorinated PE; acrylic engineering plastics polymers; ethylene vinyl acetate Lubricants and mold release agents - Improve viscosity, Low (<1) PVC, PS, polyolefins reduce friction between resin and surrounding surfaces Fatty acids; alcohols and amides; esters; metallic stearates; silicones; soaps; waxes Plasticizers - Soften rigid polymers and make them High (20-60) PVC, cellulosics more flexible Phthalates; aliphatic di-and tri-esters; polyesters; phosphates; trimellitates Reinforcers - Improve physical properties High (10-40) Epoxy, unsaturated polyester Glass fibers, wood flours Ultraviolet stabilizers - Prevent or inhibit degradation Low (<1) Polyolefins, PE, PP, polycarbonate, by ultraviolet light PS, PVC Hindered amines; hydroxybenzophenones; carbon black; hydroxybenzotriazoles (a) Additive concentration in final product (pounds additive per 100 lb of resin), ranked high, moderate, or low. source: http://www.epa.gov/owowwtr1/OCPD/PLASTIC/2-add.html 15apr03
Table 3. Polymer Densities.
[Adapted from EPA (1990a) and Anon. (1988a)]
Density
Resin (g/mL)
Thermoplastic Resins
Polystyrene (PS) 1.04-1.08
Other styrenics [e.g., styrene-butadiene and 1.05-1.14
styrene-based latexes, styrene-maleic
anhydride (SMA), styrene-butadiene (SB)
polymers]
Low-density polyethylene (LDPE) 0.89-0.94
Thermoplastic polyester polyethylene
terephthalate (PET) 1.29-1.40
Polyvinylchloride and copolymers (PVC) 1.30-1.58
Polyamide (nylon) 1.07-1.08
Acrylonitrile/butadiene/sytrene (ABS) 1.01-1.08
Polypropylene and copolymers (PP) 0.89-0.91
Thermoplastic elastomers NA
Acrylic 1.17-1.20
Polycarbonate 1.2
Cellulosics 1.09-1.24
Polyacetal 1.41-1.42
Other vinyls (e.g., polyvinly acetate, 1.16-1.35
polyvinyl butyrol,
polyvinylidinechloride)
Styrene/acrylonitrile (SAN) 1.02-1.08
Polyphenylene-based alloys 1.06-1.10
(i.e., modified phenylene oxide
and modified phenylene
High-density polyethylene (HDPE) 0.94-0.96
Thermoplastic polyester 1.30-1.38
polybutylene terephthalate (PBT)
Thermoset Resins
Phenolics 1.24-1.32
Polyurethane 1.17-1.28
Polyester, unsaturated 1.01-1.46
Epoxy 1.11-1.48
Alkyd 1.30-1.40
Urea and melamine 1.47-2.00(b)
Others (small-volume thermoplastic and NA(c)
thermoset resins)(c)
Sea water 1.02-1.03
Fresh water <1.015
NA: Not available.
(a) Value is for PET, PBT, and other thermoplastic polyester resins combined.
(b) Densities are for filled molding systems; values for unfilled pellets were not available.
(c) Includes polymothyl pentene (density: 0.83-0.84 g/mL), polyimide (density: 1.36-1.43 g/mL),
and polyetherimide (density: 1.27 g/mL).
source: http://www.epa.gov/owowwtr1/OCPD/PLASTIC/3-dens.html 15apr03
Table 4. Effects of Two
Additives to the Densities of Selected Commodity Resins.
[Adapted from Anon. (1988a)]
Density without Density with Polymer Additive (g/mL) Additive(a,b) (g/mL) ABS 1.01 to 1.08 1.18 to 1.61(a) Polyamide (nylon) 1.07 to 1.08 1.13 to 1.62(a) Polyethylene 0.92 to 0.975 1.18 to 1.28(a) Polypropylene 0.89 to 0.91 1.04 to 1.23(a) 1.22 to 1.17(b) Polystyrene 1.04 to 1.08 1.20 to 1.50(a) PVC 1.30 to 1.58 1.42 to 1.50(a) 1.30 to 1.70(b) (a) Additive: Fiber/flake reinforcer. (b) Additive: Particulate filler. source: http://www.epa.gov/owowwtr1/OCPD/PLASTIC/4-sink.html 15apr03
Table 5. Pellet Observations and Suspected Pellet Sources.
(PE: polyethylene; LDPE:
low-density polyethylene; HDPE: high-density polyethylene;
PS: polystyrene; PP: polypropylene)
Geographical Area of Study
Observations
Source(s) Discussed
ATLANTIC OCEAN
Southern New England (Carpenter et al., 1972)
PS pellets (0.1- to 2-mm dia) common in Niantic Bay, Buzzards Bay, Vineyard Sound, Rhode Island Sound,
Great Salt Pond, Long Island Sound, and Block Island Sound; average 0.01 to 1 pellet per cubic meter.
Pellets in several fish.
Effluent from plastics manufacturers or PS producers in southern New England.
Sargasso Sea (Carpenter and Smith, 1972)
50 to 12,000 particles per square kilometer (mean: 3500 particles per square kilometer); lowest concentrations near
the Gulf Stream.
Waste dumping from cities or cargo ships.
Cape Cod to Cape Canaveral and areas south (Colton et al., 1974; Colton, 1974)
PS and PE pellets (<5-mm dia); 61 to 148 pellets per square kilometer south of Cape Canaveral, and 8318
pellets per square kilometer between Cape Cod and Cape Canaveral.
Wastewater discharge from plastics plants. Most PS and PE pellets entered open coastal waters between
Block Island and eastern Long Island.
South Atlantic Bight from North Carolina to Cape Canaveral (van Dolah et al., 1980)
Percent occurrence of PS pellets on each cruise ranged from 15% to 34 %. Tar and pellets were widespread throughout
study area.
Shipping traffic and entrainment from other areas via currents.
Eastern Canada and Bermuda (Gregory, 1983)
In Bermuda, PE pellets averaged 5000 pellets per linear meter of beach, (occasionally >10,000 pellets per linear meter).
In eastern Canada, a maximum of 10 PE pellets per linear meter. Lifetime of pellets suspected to be as low as 3 years.
Pellets encrusted with pseudoplanktonic biota.
Released at dump sites or spillage along Atlantic seaboard, spillage during storage, handling, and transportation
activities.
Bermuda, Bahamas, and Martha's Vineyard, MA (Wilber, 1987)
>75% of neuston tows in north Sargasso Sea contained pellets. High concentrations (2000 per square meter) on Bermuda and
Bahamas beaches, where they are deposited by ocean currents. Pellets often embedded in tar balls ("plasto-tarballs").
Spillage and loss at coastal manufacturing and shipping sites.
Cape Basin area of South Atlantic (Morris, 1980)
White PE or PP pellets (3- to 5-mm dia) between 1333 and 3600 pellets per square kilometer; pellets and tarballs most
common contaminants in area.
No immediate source known other than through cargo loss.
Southwestern Cape Province, South Africa (Ryan, 1988b)
Predominance of PE and other polyolefin pellets, most of which were <10 mg. Pellets may be lost during handling and
released into the sea via drainage lines.
Pellets lost during transport or by manufacture of user products in industrial areas; may enter South Africa
via oceanic circulation from the South Atlantic.
PACIFIC OCEAN
North Pacific (Wong et al., 1974, as cited in Pruter, 1987)
Round, colorless pellets (1-5-mm dia) in 64% of tows along 35ø N longitude. Plastics industry.
Manufacturer outfalls; spillage from trucks, ships, and trains while loading or unloading; and when used as ball
bearings to move cargo.
North Pacific Ocean (Day et al., 1990)
Pellets found in 6% of total stations and 10% of stations with plastic. Collected primarily in transitional and nearshore
waters east of Japan. Highest density was 6500 per square kilometer north of Hawaiian Islands.
Not discussed.
New Zealand (Gregory, 1977)
PE and PP pellets, ovoid and spheruloid (greater than or equal to 5-mm dia); 10,000 to 40,000 pellets per meter on
beaches in narrow zone along driftline or spread across the back beach and washover flat.
Spillage at ports or via streams and storm water drainage after spills at inland processing plants.
Alaska (Day, 1980 and Jarrell, pers. commun. as cited in Day, 1980)
Substantial amounts of pellets; PE common but PS unknown. Also reported approximately 500,000 lb of PP pellets were
dumped into the ocean during a dock strike in Costa Rica.
Effluent of plastic manufacturers and during loading and unloading of ships at ports.
North Pacific Ocean (Day et al., 1986)
Highest densities of plastic debris along 40ø N; pellets comprised 0.5% of all plastic debris and occurred at nearly 4%
of the stations.
Not discussed.
North of Hawaii (Dahlberg and Day, 1985)
Pellets in neuston samples collected along latitudes 31ø N and 34ø N; densities must be relatively high to have been
collected at all.
Not discussed.
North Pacific Ocean and Bering Sea (Day and Shaw, 1987)
Very low concentrations of pellets in the subarctic Pacific, especially near the Alaskan coast.
Not discussed.
MEDITERRANEAN SEA
Beaches of Lebanon (Shiber, 1979)
PE, PS, and polymethyl methacrylate pellets fairly common on most beaches. Predominant pellet shape was oval to round
(2- to 5-mm dia).
Waste disposal by several plastics factories or cargo lost at sea.
Beaches of Costa del Sol, Spain (Shiber, 1982)
Pellets (2.7 to 4.5 mm) present on all beaches sampled (13); abundant on four beaches and common on most others.
Mostly LDPE (87%), HDPE (8%), and ethylvinyl acetate (4%). Encrusting biota absent on pellets, indicating recent
introduction to marine environment.
Careless disposal practices at seven nearby plastics factories, or loss during sea shipment and cargo unloading.
Coast of Spain (Shiber, 1987)
Spherules in great variety of shapes and colors, often tar-covered, abundant on most beaches. Pellets found were
predominantly PE.
Some correlation between abundance and location of 190 plastics factories in area; cargo loss during transport
in Atlantic Ocean and Mediterranean Sea.
GULF OF MEXICO AND CARIBBEAN SEA
Costa Rica and Caribbean Sea (Carr, 1987)
Large numbers of pellets on green sea turtle nesting beach in Costa Rica.
Industrial wastewater.
Padre Island National Seashore (Cole et al., 1990; Miller, pers. commun.)
All pellets were white and the same size and shape; 73% of plastic debris and 69% of all debris were pellets.
Unclear whether from single or multiple discharges or from a spill.
ESTUARIES, HARBORS, AND OTHER COASTAL AREAS
Harbors of the United States (Trulli et al., 1990; EPA, 1990b, 1992a,b; Redford et al., 1991) Many different
resins in assorted sizes, shapes, and colors found in all harbors studied except Mayagüez, PR. Hundreds to
hundreds-of-thousands of pellets in each harbor.
Industrial and municipal storm water and CSO discharges.
Kahana Bay, Oahu, Hawaii (EPA, 1992b)
Average of 105 pellets per m2 were present between low and high tide lines, concentrated mostly among other
anthropogenic and natural debris near high tide lines. Pellets appeared clean but weathered, likely polyethylene.
Commercial shipping or carried by ocean currents from distant land-based sources.
Sanitary systems in Philadelphia, PA and Boston, MA (EPA, 1992c)
Many pellet types collected in storm water outfalls and in scum samples from sewage treatment plant.
All clean, PE pellets collected at one storm water outfall.
Storm water discharges from plastics industry.
Sewage outlet pipes at factories near Long Island, NY (Hays and Cormons, 1974)
1- to 13-mm-dia PS pellets found as far as 1.1 km downstream of one industrial outfall. PE pellets also found
near outfalls in MA, CT, and NJ.
Industrial effluent.
Bristol Channel, UK (Morris and Hamilton, 1974)
0 to 20,000 PS pellets per square meter unevenly distributed in sediments. PS beads incorporated into polychaete
tubes, and becoming common in plankton samples.
Effluent from a PS manufacturer.
Severn Estuary and Bristol Channel, UK (Karter et al., 1973, 1976, as cited in Pruter, 1987)
In 1973, 1-mm PS pellets found in mud, sand, and on cooling water intake screens at nuclear power plants.
Many polychaete worm tubes constructed almost entirely of pellets. PS spherules found in some flounder.
By 1976, pellets virtually absent in all locations noted in 1972 and 1973.
Effluent from plastics industry.
source: http://www.epa.gov/owowwtr1/OCPD/PLASTIC/5-geog.html 15apr03
Table 6. Pellets Found during
EPA Aquatic Debris Programs.
[Adapted from EPA (1990, 1992a,b,c), Trulli et al. (1990); and Redford
et al. (1992)
Survey I Area Sampled Number Percent
Harbor Studies Program (a)
Boston I Charles River 2,684 30
Chelsea River 0 0
Mystic River 7 2
President Roads 10 6
Weymouth/Neponset Rivers 0 0
Boston II Charles River 453 23
Chelsea River 2 1
Mystic River 45 6
President Roads 0 0
New York I Manhattan Island 2,039 25
The Narrows and Lower Bay 461 8
New York II Manhattan Island 617 21
The Narrows and Lower Bay 548 27
Staten Island 7,601 78
Philadelphia Schuylkill River 461 32
Delaware River - Camden 197 23
Delaware River - Phila. 219 42
Mid-Atlantic Bight Wilmington Canyon to 1 5 (b)
Norfolk Canyon
Baltimore I Inner Harbor 600 20
Middle Harbor 110 12
Patapsco River 70 15
Baltimore II Inner Harbor 2,625 46
Middle Harbor 524 27
Baltimore III Inner Harbor 1,972 23
Middle Harbor 698 19
Patapsco River 7 4
Norfolk Elizabeth River 135 2
Hampton Roads 0 0
Miami I Miami River 56 3
Miami II Dodge Island 51 11
Little River 7 1
Miami River 68 3
Dodge Island 173 18
Nearshore Atlantic 1 2
Houston I Upper Ship Channel 106,759 98
Middle Ship Channel 352,790 99
Lower Ship Channel 15,660 98
Houston II Upper Ship Channel 38,199 96
Middle Ship Channel 186.936 97
Seattle Duwamish Waterway 20 8
Lake Union Ship Channel 4 1
Tacoma Commencement Bay 3,834 78
San Francisco San Francisco Bay 297 9
Oakland San Francisco Bay 279 18
Mayagüez Bahia de Mayaguez to 0 0
Puerto Real
San Juan San Juan Harbor 714 23
Honolulu Honolulu Harbor 181 5
Ala Wai Canal 2 <1
Combined Sewer Overflow (CSO) Studies Program
Philadelphia Combined Sewer Overflow 1 13
Stormwater Discharges 1,898 65
Northeast Sewage Treatment 3,420 3
Plant (d)
Southeast Sewage Treatment 49,500 24
Plant (d)
Southwest Sewage Treatment 24,880 6
Plant (d)
Boston Combined Sewer Overflow 981 11
Deer Island Sewage Treatment 810 4
Plant (d)
Chelsea Street Headworks 0 0
(Bar Screen) (d)
Ward Street Headworks 0 0
(a) EPA (1990, 1992a,b); Trulli et al. (1990); Redford et al. (1992).
(b) 20 items were collected in the Mid-Atlantic Bight.
(c) EPA (1992c).
(d) Numbers of pellets present in 100% of each facility's solid wastes,
based on collection and analysis of 10% of the solid wastes at each.
source: http://www.epa.gov/owowwtr1/OCPD/PLASTIC/6-wa31.html 15apr03
Table 7. Pellets Collected Each Day at Sewage Treatment
Facilities in Philadelphia and Boston
[EPA (1992c)]
Number Number
Location Day 1(a) Day 2(a)
Philadelphia
Northeast WPCP 2,110 1,310
Southeast WPCP 22,820 26,680
Southwest WPCP 5,520 19,360
Boston
Ward Street HW 0 0
Chelsea HW 0 0
Deer Island STP 650 160
WPCP: Water Pollution Control Plant
HW: Headworks
STP: Sewage Treatment Plant
(a): Daily totals calculated based on the analysis of 10% of the
screenings and scum present each day at each facility.
source: http://www.epa.gov/owowwtr1/OCPD/PLASTIC/7-cso.html 15apr03
Table 8. Pellet Ingestions and Potential Effects.
Geographical Location Species Reported Description of Ingestion or Effects BIRDS Alaska (Day, 1980) Northern fulmars, sooty shearwaters, short-tailed shearwaters, red-legged kittiwake, thick-billed murre, Cassin's auklet, parakeet auklet, tufted puffin, horned puffin, fork-tailed storm-petrel, Leach's storm-petrel, northern phalarope, glaucous gull, black-legged kittiwake, and least auklet. Ingestions likely due to pellet resemblance to natural prey, and will increase as annual plastics production and use of pellets increase. Some particles embedded in gizzard walls; mean residence time in gizzards may be approximately 15 months. Hydrocarbon pollutants associated with the pellets may decrease reproductive ability of seabirds. California (Chu, pers. commun., as cited in Day et al., 1985) Sooty shearwaters Ingestions Galapagos Islands (Anon., 1981, as cited in Day et al., 1985) Blue-footed booby Secondary ingestion of raw plastic. Monterey Bay, CA (Baltz and Morejohn, 1976) Northern fulmars, pink-footed shearwaters, sooty shearwaters, short-tailed shearwaters, Heermann's gull, and black-legged kittiwake. Ingestions of PE pellets in stomachs of 6 seabird species. New Zealand (Imber, pers. commun., as cited in Day et al., 1985) Great-winged petrels, kerguelen petrels, Cook's petrels, blue petrels, broad-billed prions, antarctic prions, fairy prions, Parkinson's petrels, white-faced storm-petrels, salvin's prions, and sooty shearwaters. Ingestions in low to high numbers. Chatham Islands and Gough Island (Bourne and Imber, 1982) Broad-billed prions and white-faced storm-petrels. Pellets normally found in the gizzard, and birds containing pellets often lacked food in the proventriculus. Difficult to determine whether pellet ingestion is a cause or an effect of starvation. Secondary ingestion by great skuas that consume old, pellet-containing prions. Eastern Canada (Brown et al., 1981, as cited in Day et al., 1985) Greater shearwaters and sooty shearwaters Ingestions reported. South Africa (Furness, 1983, as cited in Day et al., 1985) Greater shearwaters PS spheres ingested. Dutch coast (van Franeker, 1985) Fulmars >50% of stomachs contained pellets; toxic additives in pellets may be assimilated by birds. Midway Island and Oahu Island, Hawaii (Fry et al., 1987) Wedge-tailed shearwaters 60% of birds contained pellets (majority were PP and PE) and plastic fragments; toxicity of additives and organochlorine pollutants may be less significant hazard than obstruction/impaction of the gut of seabirds; risks to chicks may differ from risks to adults. Scottish colonies (Furness, 1985) Procellariiform seabirds (Leach's petrels, Manx shearwaters, and fulmars) Fulmars and Leach's petrels select debris according to their preference for particular prey sizes. Only equivocal statistical evidence for an influence of ingested plastic on body mass. Pellets not found in British storm petrels. Laboratory experiment. (Ryan, 1988a) Chickens Even under ideal feeding conditions, plastic-loaded birds cannot forage as efficiently as plastic-free birds. Large loads of plastic impair feeding by reducing meal size, which may, therefore, limit accumulation of fat reserves essential for reproduction, migration, and molting. Antarctica (van Franeker and Bell, 1988) Wilson's storm petrels, southern fulmars, and Cape petrels. Pellets comprised 73% of all ingested particles (combined for all species); plastic particles remaining in the gizzards of petrels may persist for months or years if not regurgitated. Decrease fitness is a likely consequence of ingestion by chicks and adults. Most plastics originate in wintering areas outside the Antarctic. South Africa and Southern hemisphere (Ryan, 1987) Blue petrels, great shearwaters, white-faced storm-petrels, pintado petrels, thin-billed prion, antarctic prion, salvin's prion, sooty shearwater, grey phalarope, arctic skua, Cory's shearwaters, grey-backed storm-petrel, broad-billed prion, kerguelen petrel, subantarctic skua, soft-plumaged petrel, great-winged petrel, Atlantic petrel, and white-chinned petrel. Three factors determine the rate of pellets (and plastic) ingestion: foraging technique, dietary specialization, and density of pellet (pollutants) in the foraging area. Procellariiform seabirds exhibit the largest plastic loads owing to foraging patterns at the sea surface. Secondary ingestion of plastic through contaminated prey is uncommon and was found only in subantarctic skua which preys on small petrels containing plastic particles. Gough Island, South Atlantic Ocean (Ryan et al., 1988) Great shearwaters (females only) Positive correlation between polychlorinated biphenyl (PCB) and plastic loads in the species; PCBs likely were derived from ingested plastic particles, and these PCBs contribute significantly to the total body load of PCBs in great shearwaters. Long Island Sound (Hays and Cormons, 1974) Gulls and terns PS pellets found in tern and gull pellets (regurgitated indigestible food). Southern Indian Ocean (Ryan and Jackson, 1987) White-chinned petrels PE pellets lost 1% of their mass after 12 days (half-life equal to at least 1 year); no instances of intestinal obstruction or physical damage to the birds; ingested plastic seldom impairs digestive efficiency in seabirds. Hawaii (Sileo et al., 1990)) Seabirds 80 species, or approximately 25% of all seabird species, are known to ingest plastic debris. Bodega Harbor, CA (Connors and Smith, 1982) Red phalaropes 6 of 7 birds contained plastic particles, most of which were PE pellets. Plastic ingestion may be producing physiological effects that threaten successful migration and breeding in regions remote from the pollution sources. Galapagos Islands and South Atlantic Ocean (Wehle and Coleman, 1983, as cited in Wallace, 1985) Blue-footed boobies, short-eared owls, broad-billed prion, and South Polar skua. Secondary ingestion of pellets from food source: blue-footed boobies and short-eared owls consumed fish containing pellets, and broad-billed prion consumed a skua containing pellets. TURTLES Texas coast (Plotkin and Amos, 1990) Loggerhead, green, hawksbill, and Kemp's ridley turtles. Pellets were ingested by eight turtles, and comprised 7% of all ingested debris. Texas coast (Amos, pers. commun., as cited in Balazs, 1985) Green turtle PE spherules in mouth of stranded, dead sea turtle. South Africa (Hughes, 1970, 1974, as cited in Balazs, 1985) Loggerhead turtles 6% of stranded posthatchlings contained pellets in stomach. Florida (Meylan, 1984, as cited in Balazs, 1985) Hawksbill turtles PS pellets and other manmade materials in stomachs. Florida East Coast and Caribbean Sea (Carr, 1987) Loggerhead and green sea turtles Resemblance to Sargassum floats may account for ingestions; young sea turtles vulnerable during open-ocean associations with Sargassum rafts; large numbers of pellets found on green sea turtle nesting beach. Hawaii and worldwide (Balazs, 1985) Sea turtles Marine turtles eat a wide variety of synthetic material, including pellets. Effects of toxic chemicals released by these materials and physical obstruction of the digestive tracts are two possible adverse impacts. Mediterranean Sea (Gramentz, 1988) Loggerhead turtles Pellets, crude oil, and tarballs apparently are ingested and excreted. Texas coast (Plotkin and Amos, 1988) Loggerhead, green, and hawksbill sea turtles PE pellets ingested by 9% of necropsied turtles; high probability that sea turtles inhabiting Texas coast will come into contact with debris. Texas coast (Shaver, 1991, pers. commun.) Kemp's ridley sea turtles 2% (2 out of 101 turtles) contained pellets; one turtle was wild and one was reared in captivity. FISH AND INVERTEBRATES Severn Estuary (Karter et al., 1973, as cited in Shiber, 1982 and Pruter, 1987) Flounder and polychaetes Ingestions by flounder. Polychaetes incorporate pellets into dwelling tubes. New York Bight (Steimle, 1991 (pers. commun.) Lobster and winter flounder Low numbers of pellets ingested, and more common in lobsters than in winter flounder. Southern New England (Carpenter et al., 1972) Grubby, winter flounder, white perch, and silversides (fish), and one chaetognath (arrow worm) PS pellets in stomachs of 8 out of 14 species of fish and one chaetognath; speculated that pellets could cause intestinal blockage in smaller fish. OTHER BIOTA North American waters (Walker and Coe, 1990) Baleen whales Suggested that filter-feeding makes baleen whales vulnerable to incidental debris ingestion; stomachs of stranded baleen whales should be examined. Canada and Bermuda (Gregory, 1983) Epibionts Epibionts on pellets include coralline algae, bryozoans, calcareous annelids, and foraminiferans. Caribbean Sea and waters off Florida (Winston, 1982) Epibionts Plastics (including pellets) encrusted with bryozoan (Electra tenella); success of this species on the east coast attributed to its colonizing of drifting smooth-surfaced plastic. ESTHETIC AND ECONOMIC EFFECTS New Zealand (Gregory, 1977) Humans Concentrations ranged from <1 pellet per meter of beach to >20,000 pellets per meter, and may lead to esthetically displeasing plastic sand beaches. Worldwide (Wallace, 1985) Humans Pellets have a negative effect on recreational activities; economic impact due to loss of raw materials that must be replaced. Bermuda (Wilber, 1987) Humans Beachgoers shocked by the presence of high numbers of pellets; pellets and plastic fragments embed in tarballs and become plasto-tarballs. United States (Klemm and Wendt, 1990) Humans Labeled combination of plastic debris and pellets beach confetti. source: http://www.epa.gov/owowwtr1/OCPD/PLASTIC/8-biol.html 15apr03
Table 9. Comparisons of Most Commonly Used Pellet Bags.
Sealing Puncture Retention Cost per Bag Material Opening Method Ranking(a) Ranking(b) bag ($) . Polypropylene woven Open mouth Sewn 1 1 0.27 to 0.32 Polypropylene woven Valve Self-sealed 1 2 0.45 to 0.55 Paper (4-ply paper, 1-ply polyethylene liner) Valve Self-sealed 2 2 0.35 to 0.40 Polyethylene form-fill and seal (FF and S) Open mouth Heat-sealed 3 1 0.25 to 0.30 (a) Ability to resist puncturing. 1: Greatest, 3: Least. (b) Ability to retain pellets with minimal loss when bag is not broken. 1: Greatest, 2: Least. Source: United DC: Mr. Marc Levine (President), personal communication, 30 July 1991, Houston, TX. source: http://www.epa.gov/owowwtr1/OCPD/PLASTIC/9-bags.html 15apr03
Table 10. Summary of Recommendations to the Plastics Industry According to Industry Sector.
Tran Recommendation Prod Pack Proc Management Adopt and implement SPI's Pellet Retention Environmental Code. ■ ■ ■ Conduct self evaluations to identify problem areas. ■ ■ ■ Encourage information sharing between companies. ■ ■ ■ Continuing developing educational materials. ■ ■ ■ Tran Recommendation Prod Pack Proc Education and Training Educate key officials and company managers regarding the fate ■ ■ ■ and effects and the economic disadvantages of pellet loss. Educate company employees regarding environmental hazards and ■ ■ ■ employee responsibility for corrective actions. Train pellet handlers to operate equipment, particularly fork ■ ■ ■ lifts, in a manner that minimizes the potential for pellet loss. Train longshoremen and other cargo handlers regarding proper ■ pellet handling procedures. Tran Recommendation Prod Pack Proc Equipment and Facilities Install a containment system to capture storm water runoff. ■ ■ ■ Improve dry cleanup procedures. ■ ■ ■ Install connecting hoses equipped with valves that will close ■ ■ ■ automatically when the connection is broken. Direct the water flow from rail hopper cars and bulk trucks ■ through a screen to capture the pellets rather than spilling them onto the ground. Seal expansion joints in concrete floors with a flexible ■ ■ ■ material. Install alarms in the pellet conveying system. ■ ■ ■ Pave all pellet handling areas, including loading docks and ■ ■ ■ rail sidings. Place screening in storm drains. ■ ■ ■ Place control devices where they can be serviced without ■ ■ ■ losing pellets. Equip bag-handling stations with vacuum hoses to facilitate ■ ■ ■ spill cleanup. Use tarps or containment devices to collect pellets as they ■ ■ ■ are spilled. Install grating at doorways for wiping feet. ■ ■ ■ Modify loading systems so that transfer lines can be ■ ■ completely emptied, with any residual resin being contained when loading ceases. Tran Recommendation Prod Pack Proc Routine Operations Place portable screens underneath connection points when ■ ■ ■ making and breaking all connections. Place permanent screens along the exterior edge of ■ the loading docks. Completely empty transport and storage vessels before ■ ■ disconnecting from the conveying system. Supervise longshoremen and other cargo handlers during ■ cargo loading and unloading to ensure proper pellet containment. Inspect cargo immediately upon receipt and note the ■ ■ condition of shipping containers and parcels on the carrier's receipt. Inspect seals on rail hopper cars before unloading. ■ ■ Check outlet tubes for pellets before moving rail hopper ■ ■ cars or trucks. Secure outlet caps and seals before moving full or empty ■ ■ ■ rail hopper cars and trucks. Insist on handling procedures that minimize punctures ■ ■ ■ and pellet spillage. Do not sweep pellets off loading docks and into the water. ■ Repair punctured bags immediately ■ ■ ■ Tran Recommendation Prod Pack Proc Maintenance and Housekeeping Improve daily and routine housekeeping and spill response ■ ■ ■ procedures. Develop SOPs for containing and cleaning up spills. ■ ■ ■ Conduct routine inspections for the presence of loose pellets ■ ■ ■ on the facility grounds, including parking lots, drainage areas, driveways, etc. Tran Recommendation Prod Pack Proc Packaging Design puncture-resistant shipping containers. ■ ■ Use reinforced bags and line containers with ■ ■ puncture-resistant material. Minimize the use of valved bags, or seal valved bags ■ ■ immediately after filling. Use sea containers instead of break bulk packaging. ■ ■ Improve palleting methods. ■ ■ Tape leaks or replace leaking bags immediately. ■ ■ ■ Inspect pellet packaging before offloading. ■ ■ Tran Recommendation Prod Pack Proc Shipping Vehicles Use containers for cargo shipping rather than ■ ■ individual pallets. Identify the person responsible for sealing the ports on ■ ■ rail hopper cars and bulk trucks, and document sealing. Close and secure the rail hopper car valve with strong wire ■ ■ ■ or aircraft cable in addition to the normal sealing mechanism. Visually confirm that each compartment and tube of shipping ■ ■ vehicles is empty. Inspect interiors of trailers and sea containers for ■ ■ defects that may puncture pellet packaging. Consider vandalism exposure when selecting leased ■ ■ track sites. Avoid on-deck pellet stowage. ■ Do not jettison pellets or containers of pellets. ■ Seal empty rail hopper cars and bulk trucks before returning ■ ■ them to shipper. Tran Recommendation Prod Pack Proc Recycling and Waste Disposal Store waste pellets in properly labeled containers. ■ ■ ■ Inspect and confirm proper handling and storage procedures ■ ■ ■ if an outside vendor is used for waste removal. Recycle or resell waste pellets. ■ ■ ■ Check broken and discarded packaging for residual pellets. ■ ■ ■ Prod: Producers. Tran: Transporters. Pack: Contract packagers. Proc: Processors. source: http://www.epa.gov/owowwtr1/OCPD/PLASTIC/10-recs.html 15apr03
[Table of contents | Executive Summary | Sections 1 · 2 · 3 · 4 · 5 · Glossary | Tables | References ]
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