NYC-WTC_000230735

NYC 9/11 Public Portal Document

TEE NEW YORKTlMES/i FRIDAY, OCTOBER 26, 2001

Safety Questions Remain About Air at Ground Zero By KIRK JOHNSON ; Air quality in Lower Manhattan Sion said. The fire, which has burned The chief of the E.P.A.’s Air Pro­ has gradually improved since the more or less constantly since Sept., grams Branch in New York, Ray­ early days after the World Trade 11, is fed by the huge compilation of mond Werner, said that poDution Center disaster last month, when a buried office material and the added ■ generated at ground level is not the gritty, acrid residue of combustion oxygen that becomes available when only thing that can account for ele­ and dust hung over parts of the city some of the ruins are removed. vated particulate counts. Some in­ like a shroud. But at certain times, Regardless of the mix, he and oth­ creases have also occurred during under certain conditions — usually er experts say that atmospheric con­ the recent warm days, he said, when for brief periods — the bad air still ditions in late fall, which tend to keep sunlight has reacted photochemical- re turns. a lid on air circulation in the city. ly with gases in the atmosphere to * Most health experts are not terri­ could make nighttime air pollution produce more particles. bly alarmed about the effect of these worse, or at least more frequent, in Meteorologists say that in general, episodes on a generally healthy pop­ coming weeks. One of the highest New York's air is at its worst in the ulation. Although many people re­ fall. The prevailing winds of sum- , main concerned about the smells and one-hour readings in recent weeks mer, which tend to blow in from the , dust that can make eyes and throats for fine particulate matter in the Atlantic Ocean, have quieted, and the bum, and anxious that conflicting Trade Center area was recorded at 2 prevailing winds of winter, which Information has left them at risk, a,m. last Friday, for example, by a ' bring storms from the west, have not health experts say that because the monitor at Pace University, yet begun. spikes do not last long and often Dr. Thurston, in particular, has Another variable is that New York occur in the middle of the night when argued that watching the weather City is big enough to generate its own few residents or office workers are forecast should become a part of the unique weather, once again often to on the streets, most people need not cleanup operation, and that adminis­ ■ the detriment of its air. Robert Born­ worry. Workers at the cleanup site trators should consider suspending stein, a professor of meteorology at itself, of course, are still advised to work at times when unfavorable air San Jose State University, who has wear respiratory protection. patterns emerge. Other air-quality extensively studied New York City's But the deeper questions that sci­ groups, like the American Lung As­ Weather patterns, said that as colder entists and physicians are posing — sociation, have argued ' that the ■weather settles on the region, the where exactly the fouled air is com- cleanup project itself should be made heat generated by thousands of tag from and what fosters its resur­ |Cleaner through technologies and building furnaces creates what is gence, often in the darkest hours |fuels that would reduce diesel emis- called a heat island effect, which before dawn — constitute something draws in colder air from areas of a downtown mystery. . ' jsions. Officials at the Federal Environ­ around the city. '■'The prime suspects include, logi­ "Pollution gets drawn toward the cally enough, the smoke from the mental Protection Agency say the still-smoldering ruins, hut also the iissues of particulate pollution and center,” he said. many diesel vehicles operating in [Lower Manhattan weather patterns suid around the site. The peculiarities are not that simple. They say that of the weather In the city in mid-to federal health standards for fine par- late fall add yet another wrinkle of iticulates have never been exceeded complexity, researchers say. at any of the agency’s monitors for "This is an unusual case," said Dr. .any period averaged over 24 hours George D. Thurston, an associate since Sept, li, and that no health professor of environmental medicine istandards have been established for at New York University - School of short-term surges because the harm­ Medicine, which has set up its own ful health effects of short exposures air monitoring device close to ground have not been proven. zero and alongside other monitors Some studies, though, indicate that from the federal government and some people with heart disease and other private institutions. other problems could be affected by ■ Currently, the monitors tracking 'even brief pollution spikes. pollution around the World Trade And so the federal officials say Center site are not able to distinguish they are looking into the question of how much of the so-called pollution the nighttime pattern raised by Dr. particulates are being generated by Thurston. And they are also consid­ the fire in the depths of the ruins, ering using more sophisticated air which cleanup crews have not yet . monitoring devices in the neighbor­ . reached, and the heavy diesel ma­ hoods around the World Trade Cen­ chinery at the surface, much of ter site that could help distinguish which operates around the clock. ' particulate sources. -. But there are hints and clues. Sul­ fates taken from the air samples, for instance, are probably from diesel combustion, while other components, like chlorine, could at least in part be coming from burning plastics some­ where down in the rubble, Dr. Thur-

CITY_21MC1OO_O11831666

NYC-WTC_000230735