Experts are worried that particulate matter in the air, which is in higher concentrations in North China because of the heavy fog since the weekend, may lead to various respiratory diseases including lung infections and cancer.
由于我国北方自上周末以来一直持续大雾天气，有专家担忧，空气中含有的浓度较高的颗粒物很可能会导致包括肺部感染以及肺癌在内的多种呼吸道疾病。

Shi Yuankai, vice-president of the Chinese Academy of Medical Sciences Cancer Hospital, said longtime exposure to particulate matter especially the particulate matter smaller than 2.5 micrometers (PM2.5) which can go directly to the alveoli of the lungs, is a major health hazard.
中国医学科学院肿瘤医院副院长石远凯表示，长期暴露在含有颗粒物环境中，尤其当颗粒物的直径小于2.5微米（这种颗粒物被称为PM2.5），可以直接作用于肺泡时，这种情况对人体健康构成重要威胁。

"Even if we can manage to keep the country`s smoking rate flat, the lung cancer rate is expected to keep rising for 20 or 30 years and worsening air pollution could be the major culprit," he said.
“即便我们能够使全国吸烟率保持平稳，预计在20或30年之内，肺癌发生率还是会持续上升，而愈发严重的空气污染问题将成为罪魁祸首。”他说。

Air quality in the capital has deteriorated because of the heavy fog. Beijing`s air was slightly polluted on Monday, according to the China National Environmental Monitoring Center.
由于浓雾的原因，首都的空气质量已经恶化。中国环境检测中心报告称，本周一，北京的空气质量呈轻度污染状态。

However, the United States embassy, which conducts its own measurements based on the concentration of PM2.5 in the air, rated Monday`s air in Beijing as "hazardous".
然而，美国大使馆根据其基于空气中直径小于2.5微米的颗粒物浓度而测量出的结果，则将北京星期一的空气质量等级评为“有害的”。

Zhong Nanshan, a respiratory expert and academician of the Chinese Academy of Engineering, echoed Shi`s concern.
呼吸内科专家兼中国工程院院士钟南山对石远凯的担忧表示认同。

He said that without intervention, PM2.5, a major cause of choking smog, would replace smoking tobacco as the top risk factor for lung cancer.
他表示，如果不采取任何措施的话，造成令人窒息的浓雾的主要因素之一——PM2.5将会取代吸烟，成为诱发肺癌的首要因素。

In Beijing, the lung cancer rate has increased by 60 percent during the past decade, even though the smoking rate during the period has not seen an apparent increase, said Mao Yu, deputy director of the Beijing Health Bureau.
北京市卫生局副局长毛羽说，在过去十年中，北京的吸烟率并没有显著提高，但肺癌的发病率却上升了60%。

"Increasing air pollution might be largely blamed for that," said Zhi Xiuyi, director of the Lung Cancer Treatment Center at Capital Medical University.
“这很大程度上要归咎于日渐严重的空气污染。”首都医科大学肺癌诊疗中心主任支修益说。

"The smaller the particle, the more hazardous it is for public health," Shi Yuankai said. "Worse, protective measures like wearing face masks barely help because the particles are too small."
“颗粒越小，其对公共健康造成的危害就越大。”石远凯说，“更糟糕的是，因为颗粒太小，像戴口罩这样的保护性措施几乎不会起到什么作用。”

The disastrous effects of smog are nothing new.
这种由浓雾引发的灾难效应已不是什么新鲜事了。

In the winter of 1952, dense smog in London caused mainly by heavy coal combustion killed about 12,000 people in the city.
1952年冬天，由于人们过度烧煤造成伦敦当地的烟雾浓度过大，致使约1.2万人死亡。

That incident prompted the British government to move to clean up the air, and the effort paid off, for today, PM10 concentrations read at the significantly lower level of around 30 micrograms per cubic meter in the city.
该事件促使英国政府进一步采取行动来净化空气。而他们的努力得到了回报，如今伦敦市的PM10浓度（直径小于10微米的颗粒物）明显下降到一个比较低的级别，每立方米只有30微克左右。

According to the World Health Organization, the main components of particulate matter are sulfate, nitrates, ammonia, sodium chloride, carbon, mineral dust and water.
据世界卫生组织称，微粒物的主要成分为硫酸盐、硝酸盐、氨、氯化钠、碳、矿物性粉尘和水。

Even in the EU, average life expectancy is 8.6 months shorter due to exposure to PM2.5, though the lung cancer rate has slightly decreased there in recent years, studies found.
研究发现，即使是在近年来肺癌发病率略微下降的欧盟国家中，其平均寿命也因为暴露在PM2.5环境中的原因而缩短了8.6个月。

"It is possible to derive a quantitative relationship between pollution levels and specific health outcomes," according to a 2005 World Health Organization report. Yet, in China, "we have few such studies", said Shi Yuankai.
“污染程度和具体的健康状况之间可能存在某种定量关系。”一份于2005年发布的世界卫生组织报告中提到。但在中国，“目前我们还很少进行这样的研究”，石远凯说。