Fresh air polluted by exhaust fumes and industrial emissions causes lung cancer, a team of World Health Organization experts has officially declared.

Traffic, power stations, industrial and agricultural emissions, and cooking and heating in the home are the main causes of air pollution. Outdoor air pollution was officially classified as carcinogenic to humans by the cancer arm of the WHO after a review of the latest scientific evidence from around the world.

The latest available data suggest that in 2010, air pollution was responsible for the deaths of 223,000 lung cancer patients around the world.

Scientists from The International Agency for Research on Cancer (IARC) studied more than 1,000 academic papers on polluted air and, separately, small particles found in polluted air. They had previously classed a variety of individual chemicals and mixtures found in polluted air as carcinogens, such as diesel engine exhaust, solvents, metals, and dusts.

Although the findings do not come as a surprise, they are likely to significantly increase the pressure on governments around the world to tackle pollution, which has risen rapidly around the world during industrialization and was already known to raise the risk of conditions like heart and respiratory diseases.

Comprehension

1.       Which of the following cause does NOT mention in the passage?

A.     traffic

B.     gas station

C.     power station

D.    industrial and agricultural emissions

2.  What do you think the meaning of ‘arm’ ( paragraph 2) is?

A.     one part of our body

B.     a weapon

C.     a branch of some organization

D.    an equipment 

3.  How many individual chemicals and mixtures did IARC class as carcinogens?

A.     2         

B.     3

C.     4

D.    5

4.  What’s the best title for this passage?

A.     The Cause of Heart Disease

B.     Air Pollution Causes Cancer

C.     The Current Environment Condition

D.    The Cause of Lung Cancer

Background Information

PM2.5是指大气中直径小于或等于2.5微米的颗粒物，也称为可入肺颗粒物。被吸入人体后会直接进入支气管，干扰肺部的气体交换，引发包括哮喘、支气管炎和心血管病等方面的疾病。

细颗粒物（Particulate）泛指悬浮在气体当中的微细固体或液体。在城市空气质量日报或周报中的可吸入颗粒物和总悬浮颗粒物是人们较为熟悉的两种大气污染物。可吸入颗粒物又称为PM10，指直径等于或小于10微米，可以进入人的呼吸系统的颗粒物；总悬浮颗粒物也称为PM100，即直径小于和等于100微米的颗粒物。

对于环境科学来说，悬浮粒子特指空气中那些微细污染物，它们是空气污染的一个主要来源。当中小于10微米直径的悬浮粒子，被定义为可吸入悬浮粒子，它们能够聚积在肺部，危害人类健康。直径小于2.5微米的颗粒，对人体危害最大，因为它可以直接进入肺泡。科学家用PM2.5表示每立方米空气中这种颗粒的含量，这个值越高，就代表空气污染越严重。

Vocabulary

tackle v. 处理，应对

industrialization n. 工业化

respiratory disease  呼吸道疾病

diesel engine exhaust柴油机排气

solvent  n. 溶剂

IARC 国际癌症研究机构

be responsible for 为……负责

power station 电力站

carcinogenic adj. 致癌物的

arm 此处指分支机构、部门

exhaust fume 废气

industrial emission  工业废气

declare v. 宣布，宣告

Keys to the comprehension

1.       B  由第二段首句可得知，gas station没有提及

2.      C 文中指世界卫生组织（WHO）的某个部门

3.      C 可由第四段末句得知

4.      B  A选项文中并未进行阐述；C选项标题太大，文中只说明空气污染对肺癌产生的负面影响；D选项文中只提及其一，肺癌还有其他引发原因