National Geographic : 1991 May
eliminate excess packaging with the same fervor as the most ardent environmentalists. The standard technique for edging out the competition is light weighting-making the same item with less material. The two-liter soda bottle that was 68 grams in 1977 is now 51 grams; plastic gallon milk jugs have gone from 98 to 60 grams. Lighter means not only thinner but also more crush able. There are indeed more plastic products, but they have not grown faster in volume than refuse overall. Glass too has been light weighted into thinner containers. A third landfill myth relates to biodegradability-the decom position of trash through the action of microorganisms. We cher ish a faith that this process flourishes in every landfill. In our trash analyses we began to notice that so-called perish ables survived surprisingly long times: a mound of guacamole thrown out in 1967, leaves raked up in 1964, lumber from 1952. One of the most common foods preserved in landfills? Hot dogs-their preservatives really work! Organics will biodegrade eventually, producing methane and other gases, but it can be a slow process. This is hard for us to accept, because we all know how food and yard wastes break down in compost piles. But landfills are not big compost piles. We chop up organic material for compost, add fluids, regularly turn the whole batch, and therefore harness the appetites of voracious aerobic microorganisms-the oxygen users. In landfills, refuse is rarely - k shredded, large quantities of 0 J* / fluids are often prohibited, ;NJR u. and circulation is usually nil. T. , &iMAHiATTAN Little air circulates around the NEW YORK waste material in these closely .LONG Sa b compacted environments, so . V_ only the anaerobic microor l'' ganisms can flourish. As SJames Noble of Tufts Univer Ss sity's Center for Environmen SATIANTI <CFAN tal Management says, "It is SCARTOGRAPHIC DIVISION not surprising that everything doesn't biodegrade rapidly; the miracle is that anything biodegrades at all!" Where food is concerned, it's astonishing how much we can learn about a household's economic and ethnic characteristics. For instance, asparagus is a strong indicator of affluence: The more of the lower stalk you cut off, the richer you are. A scorched Mexican TV dinner must have come from an Anglo because few Hispanics would ever buy it. Mexican food is gener ally made fresh, and from a relatively small assortment of ingre dients. So Hispanic households usually waste very little food. Food waste also tells whether public-health education efforts have been successful. For instance, in 1982 the National Academy of Sciences published a report linking cancer and fats. All the communities we were studying-Marin County, Califor nia, a retirement community in Arizona, and Tucson-cut their purchases of steaks, roasts, and chops because of visible fat. What replaced them? More sausage and luncheon meat products with substantially higher fat content. And fear of 126 Neva Yor's, Great Pile; Half of whatNew York City throws out weekly-100,000 tons- ends up at Fresh Kills, 14 miles from Manhattan. Sprawling over 3,000. acre of Staten Island, this isthe world's largest landfill. It holds 2.4 billion cubic feet of refuse - more than 25 times the volume of the ' SGreat Pyramid at Giza (r-lght)'. Sited on asalt marsh in 1948, ihe facilIty lacks modern compre hensive pollution controls. Before recent cleanup, more than a million Gallons of its fluids,-called leachate, seeped into nearby waters daily.