Monday, March 28, 2011

USA - polystyrene foam cups and plates use less energy, water than paper or corn-based alternatives


A new peer-reviewed study finds that commonly used cups, plates and sandwich containers made of polystyrene foam use significantly less energy and water than comparable paper-based or corn-based (polylactic: PLA) alternatives, primarily due to polystyrene foam's much lower weight.

The life-cycle inventory and greenhouse gas emissions study compares average-weight polystyrene foam, paperboard and PLA cups used for hot (16 ounce) and cold (32 ounce) drinks, 9-inch dinner plates and "clamshell" sandwich containers. 2 Researchers modelled energy consumption, water use, solid waste (by weight and volume) and greenhouse gas emissions for each product resulting ! from production, transportation and disposal. Some key findings:

Energy use: Polystyrene foam products consume significantly less energy than the alternatives-half as much as wax-coated paperboard cups and one-third as much as PLA clamshells. Water use: Polystyrene foam products use significantly less water than the alternatives-up to four times less than PLA clamshells.

Solid waste: Polystyrene foam products create significantly less solid waste by weight than the alternatives-up to five times less than paperboard and PLA products.

Polystyrene foam cups for hot drinks create less waste by volume than the alternatives-significantly less than paperboard cups with corrugated sleeves used for insulation.

Greenhouse gases: Polystyrene foam products generate slightly more greenhouse gas emissions than PLA products, expressed as net CO2 equivalents. If paperboard products do not degrade after disposal, they store carbon and generate fewer greenhouse gas emissions than polystyrene foam products; however, if paperboard products degrade to the maximum extent, they generate more greenhouse gas emissions than polystyrene foam products, so comparisons of greenhouse gas emissions vary widely depending on assumptions about the degradation of paperboard products.


The study's authors found that lower weight products with similar functionality-such as polystyrene foam products composed of more than 90% air-generally produce smaller environmental burdens.Although PLA is corn-based, the study notes: "According to the [PLA producer] NatureWorks LLC website, PLA does not biodegrade in landfills."Copies of the report on the study Life cycle inventory of foam polystyrene, paper-based, and PLA foodservice products (0.8 MB) can be downloaded from: http://www.blogger.com/ht!%20tp:/plasticfoodservicefacts.com/Life-Cycle-Inventory-Foodservice-Products

Tuesday, March 01, 2011

World - bottled water: a ridiculous waste?

Bottled water has been a big-selling commercial beverage around the world since the late 1980s. According to the Worldwatch Institute, global bottled water consumption has more than quadrupled since 1990. Today Americans consume over 30 billion litres of water out of some 50 billion (mostly plastic) bottles every year. The Beverage Marketing Association reports that in 2008 bottled water comprised over 28 percent of the U.S. liquid refreshment beverage market. The only bottled drinks Americans consume more of are carbonated sodas like Coke and Pepsi.

And frankly, yes, it is a ridiculous waste that we obtain so much of our drinking water this way when it is free flowing and just as good if not better for you right out of the tap. According to the Earth Policy Institute (EPI), some 2.7 million tons of petroleum-derived plastic are used to bottle water around the world every year. "Making bottles to meet Americans' demand for bottled water requires more than 1.5 million barrels of oil annually, enough to fuel some 100,000 U.S. cars for a year," says EPI researcher Emily Arnold. And just because we can recycle these bottles does not mean that we do: The Container Recycling Institute reports that 86% of plastic water bottles in the U.S. end up as garbage or litter.


The financial costs to consumers are high, too: According to the Environmental Working Group (EWG), bottled water costs up to 1,900 times more than tap water. EWG is particularly appalled at the lack of transparency by leading bottled water sellers as to the sources of their water and whether it is purified or has been tested for contaminants. According to a recent survey by the group, 18% of the 173 bottled waters on the U.S. market today fail to list the location of their source; a third disclose nothing about the treatment or purity of the water inside their plastic bottles.

EWG recommends that consumer resist the urge to buy bottled water and go instead for filtered tap water. "You'll save money, drink water that's purer than tap water and help solve the global glut of plastic bottles," the group advises, adding that it supports stronger federal standards to enforce consumers' right to know about what's in their bottled water besides water. Until that day comes, concerned consumes should check out EWG's Bottled Water Scorecard, a free website that provides information on various bottled water brands, where they originate and whether and how they are treated to remove contaminants.

News from Health News Digest and photo from here


PS: I remember the results when we took some bottled water samples to our uni labs, the mineral readings were completely wrong and some were not deemed to be safe. Tap water is more regulated than mineral water and for this reason many say tap water whether is filtered or not is purer (healthier) for you.