Mon, Jan 10, 2000 page2

• Acid rain not just a local issue

  THE ENVIRONMENT The EPA has been accused of misusing statistics to give the public a false sense of calm as to the damage caused by acid rain in Taiwan

  • By Chiu Yu-Tzu / STAFF REPORTER
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  Walking in the rain in Taiwan might not be as romantic as it is in the movies, especially in winter, when a northeasterly wind starts to blow.

  Last December, officials at the Central Weather Bureau found that several areas in northern Taiwan had been significantly affected by pollution, recording average acid precipitation index (pH values) readings mostly lower than five, the minimum safe value according to scientists. (The lower the number, the higher the level of acidity.)

  Bureau officials pointed to an extreme case of acidity recorded at 3.6 pH in value in Keelung.

  

  Emission from factories and coal-fired power plants are responsible for the release of pollutants into the air which result in acid rain, a problem that affects whole regions, not just individual countries.

  PHOTO: CHANG CHUNG-YI, LIBERTY TIMES

  Bureau officials remind people to wear hats or use umbrellas to avoid going bald as a result of the acid rain, adding that the acidity of rain in Keelung was only slightly less acidic than vinegar.

  Contradictory information

  One month after the bureau issued the warning about acid rain, the Environmental Protection Adminis-tration (環1珓O護署, EPA) released a report that suggested that levels of acid rain were not as serious as had been widely assumed, especially compared to other countries.

  A recent EPA report said that the average acid precipitation index (pH value) nationwide during the first 11 months of last year was 5.1, above the minimum safe value 5, while Hong Kong was reported at 4.2, Japan at 4.8, the US at 4.2, and Europe at 4.1, exceeding the minimum safe value.

  Scientists said that detailed analysis of different pH values in local areas should also have been addressed.

  In addition, northern Taiwan is more severely affected by overseas pollutants than the rest of the country because of northeasterly winds," said Yuan Chung-hsin (袁??新), a professor of environmental engineering at National Sun Yat-sen University (???s?j學) in Kaohsiung.

  The EPA report added that the problem of acid rain in urban areas, including the three largest cities -- Taipei, Kaohsiung and Taichung -- had improved noticeably after the EPA started to monitor and control the sulfuric and nitric acid content of rain in 1991.

  However, scientists conducting acid rain research with the EPA's financial assistance told the Taipei Times that the administration had concealed several problems related to acid rain.

  "We cannot consider acid rain problems simply by focusing on the average acid precipitation index (pH value). Different levels of acid precipitation in different areas should been stressed," said Lin Neng-huei (林能暉), leader of the acid rain research team at theational Central University (??央?j學, NCU) in Taoyuan County.

  Lin said that the administration compared the average pH value of acid rain in Taiwan to worst cases in other countries to ease people's minds.

  "In fact, the average deposition of sulfides in Taiwan is about six times higher than that in the US," Lin said.

  An international issue

  Sulfur oxides and nitrogen oxides, thought to be carried long distances by air currents, can be converted in the atmosphere into sulfuric acid (H2SO4) and nitric acid (HNO3), generally called "acid rain."

  The term acid rain was coined by British scientist Robert Angus Smith in a book titled Air and Rain: The Beginnings of Chemical Climatology.

  His purpose in writing the book was to highlight local air pollution problems caused by industrial development in Manchester.

  In 1980, a program called the Long Range Transport of Airborne Pollutants (LRTAP) was established in Canada to study the long-range transmission of air pollutants and their possible environmental effects because eastern Canada had become affected by emissions for the northeastern US.

  In the 1990s, developing countries in Asia also suffered from the problem of acid rain.

  The recent acid rain report released by Taiwan's EPA also reveals that wind-blown pollutants from China and South Korea account for 25 percent of sulfur oxides in Taiwan.

  NCU professor Lin adopted a method called Long Range Transport Model Simulation to study what happens when northeasterly winds blow in winter. He concluded that it takes 48 hours for air pollutants to reach Taiwan from South Korea and 72 hours from northeastern China.

  "The frosty cross-strait relation between Taiwan and China doesn't stop the transmission of airborne pollutants," Lin said, referring the necessity of joining international organizations such as an acid rain monitoring network made up of countries in eastern Asia such as China, Japan and South Korea.

  The real situation in China

  "Taiwan's admission to many international organizations has been blocked. However, the acid rain problem cannot be solved until all countries work together, exchanging local monitoring data and research information," Lin said.

  Lin added that it was very difficult to know the real air pollution situation in China and its possible effects on ecosystems in Taiwan and other countries.

  According to a report in the New Scientist magazine in February 1999, a US scientist, Gregory Carmichael, predicted a massive ecological disaster from acid rain in Asia.

  He said, based on his study, that the acid rain falling on vast regions of eastern and southeastern China, the Korean peninsula and Japan would overwhelm the soil's' ability to cope by 2020, if there is no change in existing emission-control policies.

  An article in Time magazine last March indicates that the burning of high-sulfur coal in southern China produces a poisonous drizzle, which affects 30 percent of the country.

  A 1993 study, cited in the report, found that nearly one-quarter of vegetable crops in the Chongqing area had been damaged by acid rain.

  What can be done locally?

  Lin said a cross-strait conference on acid rain will be held here in May, co-sponsored by the Mainland Affairs Council. He said that this would be an excellent opportunity to exchange information with experts in China.

  Yuan agreed that such a conference would have beneficial results.

  "At several cross-strait conferences on air pollution, scientists from both sides of the Taiwan Strait have tended to put forward their own government's position on the issue instead of focusing on the issue itself," Yuan said.

  Yuan said that a scientist from Fujian province once stated that 30 percent of wind-blown pollutants in Fujian came from Taiwan without providing any precise scientific data.

  "Based on the lack of pollutant monitoring data, scientists would not be able to reach such a conclusion," Yuan said.

  However, Yuan stressed that several acid rain prevention strategies could be carried out locally to limit hazardous gas emissions and adopting the use of low-sulfur oil products.
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