by clicking the arrows at the side of the page, or by using the toolbar.
by clicking anywhere on the page.
by dragging the page around when zoomed in.
by clicking anywhere on the page when zoomed in.
web sites or send emails by clicking on hyperlinks.
Email this page to a friend
Search this issue
Index - jump to page or section
Archive - view past issues
FLEXO Magazine : April 2010
34 FLEXO april 2010 www.flexography.org at which the survivability of native organisms are impaired. In addition, a decrease in pH can cause heavy metals in sur- rounding geology to leach into the water, potentially causing additional damage to the local environment. Nitrogen oxides are emitted during the combustion of any fossil fuel, while sulfur dioxide chiefly comes from coal combustion. Eutrophication of water. This is the process of nutrient enrichment—primarily phosphorus (P) and nitrogen (N)—in a body of water. Due to the increased food supply, a eutrophic body of water will commonly spark rampant algal growth, which in turn causes high turbidity, low dissolved oxygen lev- els and inhibits the penetration of sunlight into the water. All of these reduce the suitability of the water for most life forms and human recreation. Common causes of eutrophication include agricultural runoff, sewage inputs, industrial emissions, and atmospheric deposition. Global warming. Although still the topic of debate in some circles, this parameter reflects the increase in a plan- et’s average tropospheric (near-surface air) temperature. This can be exacerbated by high concentrations of heat- trapping compounds, known as greenhouse gases, in the atmosphere. These include carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), chlorofluorocarbons (CFCs), and stratospheric ozone (O3). These gases are predominantly generated by fossil fuel combustion, agricultural activities, and some industrial operations. Ozone depletion. This parameter refers to the destruction of the stratospheric ozone layer, which filters out the most intense ultraviolet light from the sun’s radiant energy. Human exposure to UV wavelengths can cause damage to the eyes and skin. Ozone depletion occurs when chlorinated organic compounds, mainly CFC’s (chlorofluorocarbons), are emitted into the atmosphere. When activated by UV light, CFCs can release chlorine atoms that destroy ozone (O3) molecules. The US EPA is currently phasing out the use of these compounds, but CFC’s are still employed in refrigerants, air conditioning units, some cleaning solvents, and other products. Smog generation. This is the formation of photochemi- cal smog in the troposphere (near-surface air). A myriad of respiratory and ocular health impairments are caused by smog, including itchy eyes, a sore throat, headaches, and asthma. Additionally, inhibition of the immune system can occur, potentially resulting in chronic bronchitis or emphy- sema. Smog forms from the reaction of nitrogen oxides (NOx), oxygen (O2), and volatile organic compounds (VOCs) in the presence of sunlight. Chief sources of NOx and VOCs are the use of internal combustion engines, as well as some industrial processes. Nitric oxide also come from electricity generation and fossil fuel combustion, while VOC’s are emitted by prod- ucts which contain solvents. SAVINGS IN COMPARISION In addition to the multiple impact categories, the EAC also converts the impact numbers into some more concrete terms that make it a bit easier to understand the magnitude of the impacts. These include: Cars operating for one year. This comparison is calcu- lated based on the total emissions of carbon dioxide (CO2) equivalents released by the product’s lifecycle from cradle to gate. The factor used for this computation is 0.520 kg CO2 per car per year, assuming a car drives 12,500 miles annually. 4 Gallons of oil. This comparison is calculated using the total energy consumption over the product’s lifecycle from cradle to gate, essentially the Energy Consumption value under Impact Categories. It is assumed that one gallon of oil provides 146 MJ (40.6 kWh) of energy.5 Households powered for one day. This measure is essen- tially the Energy Consumption value under Impact Catego- ries. The computation is performed under the assumption that the average U.S. household uses 278 MJ/day (77 kWh/day), based on figures from the U.S. Energy Information Adminis- tration (2009).6 Laundry washloads. This reflects the Water Consumption value under Impact Categories. It is assumed that each load uses 15 gal, which is the current EPA Energy Star standard for a washing machine (EPA 2009).7 IMPACt ASSeSSMeNt Once the user inputs his or her unique variables into the EFC, the calculator computes results for each of the environ- mental impact categories listed above. Additionally, the user FIGuRe 2: The composition of power grids across the U.S. varies widely. Others Wind Solar Hydro Geothermal Waste Peat Solid biomass Gaseous biomass Nuclear Natural gas Heavy fuel oil Hard coal Brown coal Blast furnace gas TEchnologieS & TEchniqUeS FLXApril10_mech.indd 34 4/10/10 1:22 AM
Sustainable Winter 2010