Plastic Carrier Bags.png

This was a research project in partnership between Engr308 Technology and the Environment and the City of Arcata, during Fall 2010, to explore the impacts of single use plastic bags in Arcata, Humboldt County, California. This research helps to educate arguments over the merits of a single use plastic bag ban. This article gives more background and the following documents starts with findings then works through much of the supporting information.

Findings[edit | edit source]

Sources of embedded energy in Arcata's yearly single use plastic bags as produced by Media:Arcata Plastic Bags.xls.

The result of a brief study by the course showed that Arcatans use between 3 and 5 million single use plastic bags per year. A more in-depth study of impacts, conducted by the course, resulted in this spreadsheet that allows a user to enter values such as shipping companies, shipping ports, manufacturers, number of bags used, number of bags recycled, grid mix of manufacturer, bag materials, etc. to calculate embedded energy and emissions. At the low end of 3 million single use plastic bags per year (and other average assumptions shown in the spreadsheet), the impacts of Arcata's single use plastic bag yearly habit include:

  • Total Gallons Diesel: 380 gal
  • Total Energy: 2,209,326 MJ
  • Total Emissions
    • CO2: 1,174,423 lb
    • CO: 399 lb
    • SOx: 6,888 lb
    • NOx: 3,224 lb
    • Particulate: 7,536 lb
  • Water Usage: 185,955 gal

These impacts vary greatly depending on assumptions, which can be changed in the spreadsheet. This does not include other impacts such as quality of life, impacts on fishing, impacts on wastewater treatment pumps, and animal deaths. The spreadsheet also includes comparisons such as:

  • The energy used for 3,000,000 bags could be saved by 200 McKinleyville residents commuting to Arcata for an entire school year by bike instead of car.
  • The amount of energy used for 3,000,000 bags is equal to over 1,000 one way trips to San Francisco in a 2010 Chevy Tahoe.
  • A 50% reduction from 2010 plastic bag use in Arcata would eliminate the same amount of C02 emitted by 6,680 one-way trips from Arcata to San Francisco in a 2010 Chevy Tahoe.

Literature Review Synthesis[edit | edit source]

Existing Bag Programs: Summary and Some Results[edit | edit source]

See Plastic bag programs for existing plastic bag programs with its location, year, summary of program type, brief results, and city size.

Bag Science: Embedded Energies and Plastic Bag Use[edit | edit source]

Embedded Energies of Different Kinds of Plastics[edit | edit source]

The following table is a summary of key indicators from a LCA study in the Handbook of Biodegradable Polymers[1]


LDPE - Low density polyethylene
PET - Polyethylene terephthalate
PCL - Polycaprolactone
PLA - Polylactid
PHA - Polyhydroxyalkanoates

Type of plastic Cradle to grave
energy use (MJ per Kg)
Type of wast treatment Green House Gas emissions
(kg CO2 per kg)
LDPE 80.6 Incineration 5.04
PET (bottle) 77 Incineration 4.93
PCL 83 Incineration 3.1
Mater-Bitm starch film grade 53.5 Incineration 1.21
PLA 57 Incineration 3.84
PHA 81 Incineration Not Available

Estimate of Energy Consumption by Plastic Bags[edit | edit source]

Estimate of Energy Consumption by Plastic Bags in the Entire US, based on 500 Bags per Capita, per Year[2]

  • Producing 1 kg of polyethylene (PET or LDPE), requires the equivalent of 2 kg of oil for energy and raw material.
  • Polyethylene (PE) is the most commonly used plastic for plastic bags.
  • Burning 1 kg of oil creates about 3 kg of carbon dioxide.

In other words: Per kg of plastic, about 6 kg carbon dioxide is created during production and incineration.[3]

  • Per two plastic bags manufactured the following energy is used:
Energy used by Resource percentages
990KJ of natural gas 71%
240KJ of petroleum 17%
160KJ of Coal 12%
1390KJ total 100% total

Estimate calculation:

Energy used to manufacture 2 plastic bags (kWh):


Energy used for one plastic bag:

  1. 386kWh/2=.193kWh

U.S. plastic bag use Translated into Energy Equivalent:

U.S. per capita use of plastic bags used is estimated to be 500[4]

  1. 193kwhr*500 bags*300 million people=29 x 109kWh of energy per year

Embodied Energy Analysis - Plastic vs. Paper[edit | edit source]

The following table comes from the Boustead report, a life cycle analysis of paper and plastic bags conducted in 2007. The report was prepared for the Progressive Bag Alliance, and was conducted by Boustead Consulting and Associates. The report was reviewed by a professor of chemical engineering at North Carolina State University.[5]



Plastic Bags Paper bags

with 30% recycled content

Total energy used in megajoules 763 2622
Fossil fuel use in kilograms 14.9 23.2
Municipal solid waste in kilograms 7.0 33.9
Greenhouse gas emissions in C02 equiv. tons 0.04 0.08
Fresh water usage in gallons 58 1004

Challenges to Bag Policies[edit | edit source]

Interesting Anecdotes[edit | edit source]

  • Plastic bag bans in San Francisco and other areas have resulted in most people simply switching to paper bags. It has also resulted in law suits, and in Oakland the ban was overturned by plastic industry plaintiffs who argued that a plastic-only ban was illegal since there were no studies on the effects of increased paper bag usage. This illustrates that "plastic-only bans have proved vulnerable to legal challenges," and that if the end-state is supposed to be a complete shift to reusable bags, then there is no reason to leave paper bags out of a bag ban, especially since it renders the ban legally unstable.[6]
  • In 2 years, all 11 states which attempted to ban single use plastic bags failed.(AWAITING citation), while small community bans and blanket federal bans around the world seem to have better results.
  • The Bethel, AK example shows greater success when the community is ready and on board. In 2009 Bethel, Alaska banned plastic bags and takeout containers. Just eight years prior, voters overturned just such a ban, after an uproar from businesses. Now, with reports of plastic bags littering the tundra, in the city as well as the surrounding areas, advocates say that this time the people are ready for it.[7]
  • New Delhi example show that basing the implementation of a ban on policing a large population is not effective. Their bag ban failed 18 months after its implementation. It was too hard to enforce in a city of 16 million, in country that is in the top ten plastic bag producers, and basing a ban on policing rather than taxing or providing alternative materials. [verification needed]

Significant Interest Groups Against Bans[edit | edit source]

  • Bag manufacturers: cite paper as being just as bad for the environment, and bans create job losses in their industry.
  • Small businesses: can be expensive to implement
  • Consumer groups: inflated grocery bills, California expanding deficit
  • American Chemistry Council (ACC): think plastic bag ban is irrelevant, desire more efforts towards recycling[8]

Arguments Against Bans[edit | edit source]

  • It will increase consumer and retailer costs[9]
  • Concern about the lack of availability and quality of compostable bags[10]
  • The production of paper bags is more damaging than the production of plastic bags-the ban will do more harm than good[11]
  • Freedom of choice: Can people be told how to bag their groceries?
  • It's easy to forget your re-usable bags
  • Banning plastic bags creates job loss
  • Plastic bags are recycled

Environmental Justice Issues[edit | edit source]

The environmental justice movement was begun in recognition of the fact that: "Environmental regulations have not uniformly benefited all members of society. People of color (African Americans, Latinos, and Native Americans) are disproportionately harmed by industrial toxins on their jobs and in their neighborhoods. These groups must contend with dirty air and drinking water- the byproducts of municipal landfills, incinerators, polluting industries, and hazardous waste treatment storage, and disposal facilities."[12] Environmental justice issues also cross international borders. Many cheap products we buy in the United States are manufactured in countries that do not have stringent, or any, environmental regulations. Thus, the populations of those exporting countries are bearing the external costs associated with the production of materials we consume. Most plastic shopping bags are made in countries with lax environmental regulations, like China.[13]

Human Health Effects[edit | edit source]

  • Plastic bags can contain toxic metals (cadmium and lead) which can leach out and contaminate food[14]
    • Cadmium can cause vomiting and heart enlargement in low doses[14]
    • Lead may cause degeneration of brain tissues with long term exposure[14]
    • Polythelyne is used in the production of plastic bags and may be a carcinogen[15]
  • Plastic bags improperly disposed of clog drains, which can be the cause of floodin, which leads to water borne diseases[14]
  • When disposed of in the soil, plastic bags can prevent the recharging of ground water aquifers[14]
  • "The manufacturing of two plastic bags produces 1.1 kg of atmospheric pollution, which contributes to acid rain and smog"[13]

Environmental Effects[edit | edit source]

  • Plastics are readily combustible and when burned generate black smoke, decomposition, and volatilization products, that get incorporate into the environmental[16]
  • The plastic in the bags is environmentally stable, but the additives, their reaction and degradation products in the polymeric material can be released into the environment and into the fluids they contact, products, or food. The additives for plastics, that are released by leaching out and contact transference, have potential ecotoxic effects, mobility under conditions of use, have the possibility to accumulate in the environment or bioaccumulate in organisms, and can generate or release hazardous substances during disposal or under normal conditions.[16]
  • Plastic bags photo-degrade in land fills and the toxic particles in the plastic can enter the food chain if animals consume it.
  • Many animals mistake plastic bags for food, which can kill them. If these animals do die, their body will decompose and the plastic will stay intact, which can potentially kill another animal[17]
  • Every year over one million birds and 100,000 marine mammals and sea turtles are killed from eating or getting tangled up in plastic. There are 46,000 pieces of plastic for every square mile of ocean[18]

Urban Pollution[edit | edit source]

  • Plastic bags float into storm drains and waterways, which causes clogging
  • Plastic bags are non-biodegradable and difficult to recycle, they can jam machines during the recycling process[19]
  • In a clean up of the Los Angeles River, 43% of the total trash collected was attributed to plastic film and bags[20]
  • Retailers in California distribute 14 billion plastic bags annually[21]
  • Much of the plastic bag waste moves towards the coast, Save the Bay in the San Francisco Area said that California taxpayers spend over $25 million in the cleanup of plastic bags[22]

Great Pacific Garbage Patch[edit | edit source]

  • North Pacific Gyre is a circular pattern of currents in the Pacific Ocean
  • 80% of the garbage (bottles, toothbrushes, packaging material, etc.) is from land[23]
  • Much of the debris is small and suspended below the surface of the water[24]
  • Charles Moore, the discoverer of the gyre, described the debris as "plastic-plankton soup"[25]
  • Plastic debris can be kill marine wildlife, including: marine mammals, turtles, birds, fish, and marine organisms
  • The effect on marine life could impair the livelihoods of people who rely on marine life for food or income[26]
  • Plastic particles contain toxins, for example bisphenol A (BPA), polyvinyl chloride (PVC), and other chemicals that can seep into the water and cause negative health effects to both wildlife and humans[27]

Impact on Developing Nations and Disempowered People[edit | edit source]

  • In 2005, a monsoon flood killed 1,000 people in Mumbai, India. The intensity of the flood was attributed to the amount of plastic bags clogging gutters and sewers. Mumbai banned plastic bags in 2002, but plastic is still a big problem in their community[28]
  • Bangladesh experienced similar flooding, which led to their plastic bag ban in 2002[13]
  • Flooding creates stagnant water, which is the ideal habitat for mosquitoes and other disease spreading organisms that already attack developing nations[13]
  • In the year 2000, cows in India were dying from eating plastic bags that had been discarded, and in one town 100 cows a day were being reported as dead to to this phenomenon[29]
  • Tourism is being affected by the reduced aesthetic quality where bags end up[30]
  • Many landfills and waste incinerators are located in rural areas. These landfills can result in the seeping of toxic substances into the soil and groundwater. The smoke from burning plastics contains chemicals that can lead to serious health impacts[31]

Reusable Bags[edit | edit source]

  • Plastic totes may be more eco-friendly to produce than cotton or canvas totes that need large amounts of water and energy to create[32]
  • People may not desire reusable bags because of the expense, versus a free "disposable" plastic bag[32]
  • Some stores have started to use SmarTote reusable plastic tote bags that have a barcode tracking system that records how many uses the bag gets and enters users in contests for prizes[32]

Teams[edit | edit source]

This work in the news[edit | edit source]

References[edit | edit source]

  13. 13.0 13.1 13.2 13.3
  14. 14.0 14.1 14.2 14.3 14.4
  16. 16.0 16.1 This information according to "Combustion Products of Plastics as Indicators for Refuse Burning in the Atmosphere" Berndr T. Simoneit, Patriciam Medeiros, and Borsym Didyk.
  19. Michael Mensah Wienaah (2007) "Sustainable Plastic Waste Management: A Case Study in Accra, Ghana"
  20. Lisa Boyle (2010) "Ten Reasons Why Single-Use Plastic Bags Blow" Plastic Pollution Coalition. Accessed 23 Oct 2010.
  25. Charles Moore (2003) "Trashed: Across the Pacific Ocean, Plastics, Plastics, Everywhere" <ita>Natural History</ita> Vol. 12 No. 9
  26. National Research Council (1995) <ita>Clean Ships, Clean Ports, Clean Oceans: Controlling Garbage and Plastic Wastes at Sea </ita>Washington DC: National Academy Press, pp. 51-55.
  27. Ira Zunin (2010) "Reduce use of plastics for better health, oceans"<ita> The Honolulu Star-Advertiser</ita> Accessed 24 October 2010
  32. 32.0 32.1 32.2 This information according the article "An Inconvenient Bag" by Ellen Gamerman. Wall Street Journal. (Eastern Edition). New York, N.Y.:Sep 26, 2008. p. W.1
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