[(Title)] Study: National parks get fewer visits when pollution rises.

Sequoia National Park air resource specialist Annie Esperanza explains how ozone diminishes the view from Beetle Rock in Sequoia National Park, Calif., on May 11,

红杉国家公园空气资源专家AnnieEsperanza解释说，臭氧如何减少位于加州红杉国家公园的BeetleRock的景色。

2012. A new study concludes visitors may be steering clear of some U.S. national parks or cutting their visits short because of pollution.

一项新的研究得出结论，游客可能会因为污染而避开一些美国国家公园或缩短他们的访问时间。

Visitors appear to be steering clear of some U.S. national parks or cutting visits short because of pollution levels that are comparable to what's found in major cities, according to a study released Wednesday.

Researchers at Iowa State and Cornell universities looked at more than two decades of data on ozone pollution at 33 parks — from Shenandoah to Yellowstone, the Grand Canyon and Yosemite.

爱荷华州和康奈尔大学的研究者们研究了从神安多阿到黄石州、大峡谷和约塞米蒂的33个公园中20多年的臭氧污染数据。

They say visitor numbers dropped almost 2 percent when ozone levels went up even slightly and by at least 8 percent in months with three or more days of high ozone levels compared with months with fewer days of high ozone.

他们表示，随着臭氧水平的上升，访问人数下降了近2%，几个月内臭氧水平下降至少8%，而臭氧水平高的3天或更长时间，臭氧消耗量则少于几个月。

Study co-author Ivan Rudik said air quality warnings issued by parks and other government agencies may be causing the visitation drop.

研究联合作者IvanRudik说，公园和其他政府机构发出的空气质量警告可能会导致访问量下降。

That's consistent with previous research on so-called avoidance behavior in response to pollution alerts in other settings.

这与以往针对其他环境中的污染警报进行的所谓避险行为研究是一致的。

The study sought to control for seasonal variations and daily changes in the weather.

这项研究试图控制季节性变化和天气的日常变化。

"Even though the national parks are supposed to be icons of a pristine landscape, quite a lot of people are being exposed to ozone levels that could be detrimental to their health," said Rudik, an assistant professor of economics at Cornell.

康奈尔(Cornell)经济学助理教授Rudik说：“即使国家公园被认为是原始景观的象征，但许多人正暴露在臭氧层之中，这可能会损害他们的健康。

The study, published in the journal Science Advances, comes as national parks have seen record numbers of visitors in recent years despite concerns over pollution.

该研究发表在《科学进步》杂志上，因为近年来，尽管人们担心受到污染，但国家公园的游客数量创下纪录。

Ozone, the main ingredient in smog, is formed when small particles of pollution from cars, power plants and industrial facilities react with sunlight. It limits visibility and can cause respiratory problems.

臭氧是烟雾的主要成分，当汽车、发电厂和工业设施产生的小颗粒受到阳光的照射时形成臭氧，从而限制了可见度，并可能引起呼吸问题。

The Interior Department is backing down from a plan to impose steep fee increases at popular national parks in the face of widespread opposition from elected officials and the public.

在当选官员和公众广泛反对的情况下，内政部正在制定一项计划，要求在受欢迎的国家公园加大费用。

The plan would nearly triple entrance fees at 17 of the nation's most popular parks, including the Grand Canyon,...

这项计划将使全国17个最受欢迎的公园，包括大峡谷，的入场费增加近三倍。

In parks, ozone is carried in on the wind and also caused by traffic and other activities.

在公园里，臭氧在风中传播，也由交通和其他活动造成。

Data collected by the National Park Service show parks failed to meet U.S. air quality standards for ozone at least 85 times this year. In 2016, national parks exceeded the standard a combined 276 times.

国家公园管理局收集的数据显示，公园未能达到美国臭氧空气质量标准，至少是今年的85倍，2016年，国家公园超过了标准总量的276倍。

Park officials were reviewing the new study but had not evaluated whether ozone and visitation are linked, spokesman Jeffrey Olson said.

政府发言人杰弗里·奥尔森说，公园官员正在检讨这项研究，但没有评估是否与臭氧和探视有关。

He said nine parks issue ozone alerts when warranted — Acadia, Great Smoky Mountains, Mammoth Cave, Pinnacles, Rocky Mountain, Sequoia, Kings Canyon, Shenandoah and Yosemite.

他说九个公园在需要时发出臭氧警报——阿卡迪亚，大烟山，马莫特洞穴，平纳克，落基山，红杉，金斯峡谷，神安多阿，约塞米特。

Virginia Tech economist Kevin Boyle, who has researched ozone in parks and was a peer reviewer for the study, said it provides "strong, suggestive evidence" that air pollution is changing people's behavior when planning a park visit.

弗吉尼亚理工大学(VirginiaTech)经济学家凯文·博伊尔(KevinBoyle)表示，该研究报告提供了“强有力的、有启发性的证据”，即空气污染正在改变人们在计划参观公园时的行为。

Boyle said follow-up research is needed to confirm the findings.

博伊尔说，需要后续研究来证实这些调查结果。

Tourists also cut visits short for other air quality problems, such as thick smoke from wildfires that was blanketing Yosemite National Park this week and led to health warnings.

游客们还因为其他空气质量问题而缩短了访问时间，比如本周被约塞米蒂国家公园覆盖的野火浓烟，并导致健康警告。

Ozone concentrations nationwide have generally fallen since the Clean Air Act was amended in 1990 to address the problem, according to the U.S. Environmental Protection Agency.

美国环境保护局(USEnvironmentalProtectionAgency)称，自1990年对《清洁空气法》(CleanAirAct)进行修正以解决这一问题以来，全国的臭氧浓度普遍下降。

Yet amounts still regularly exceed national guidelines, and the researchers determined that many national parks have pollution levels similar to New York or Los Angeles.

然而，数量仍然经常超过国家准则，研究人员发现，许多国家公园的污染水平与纽约或洛杉矶相类似。

A comparison of ozone in parks to levels in the 20 most populous U.S. cities showed they were "statistically indistinguishable," according to the study.

该研究表明，将公园内的臭氧水平与人口最多的20座美国城市中的臭氧水平相比较，显示出“从统计上来说无法区分”。

At Sequoia National Park, about 200 miles north of Los Angeles, there have been more bad ozone days than in the city in all but two years since 1996, the study said.

该研究报告称，在洛杉矶以北大约200英里的红杉国家公园，自1996年以来，除两年以外，臭氧日的危害性要大于这座城市。

Park visitors who live nearby are more likely to change their plans than out-of-town visitors who have sunk money into airplane tickets, lodging and rental cars, said John Loomis,

科罗拉多州立大学的经济学教授JohnLoomis没有参与这项研究，他说，居住在附近的公园参观者比那些将钱投进飞机票、住宿和租车内的镇外游客更有可能改变他们的计划。

an economics professor at Colorado State University who was not involved in the study.

Studies of air quality alerts and the reactions they trigger among schoolchildren in England and children and the elderly in Los Angeles have reached similar conclusions.

对英国学童、洛杉矶儿童及老年人的空气质量警示及其触发反应的研究得出了类似的结论。

"You basically shift what you do" to avoid pollution, Loomis said.

Loomis说：“你基本上会改变你做的事情”以避免受到污染。