air pollution has reached such a scale that it will take a collective effort to control it .
the condition is ripe for political actions in the form of policy change , more vigorous law enforcement , and government budgetary allocation for air pollution control .
air pollution has become so annoying to the public that it is impossible to take the traditional  see no evil , hear no evil , speak no evil 
(  ,  ,  ,  ) tolerance approach that is so ingrained in the chinese confucian outlook .
breathing polluted air outdoors 50% of time does not allow people to look the other way anymore .
doing nothing or not doing anything fast enough on the part of the government will be viewed as a lack of moral responsibility .
therefore , politically , air pollution control is a must and the time is ripe to take  unpleasant  actions .
the increase in air pollution has paralleled the economic transformation of china in the past 30 years . in the last 30 years
a common argument for tolerating air pollution is that it is a  necessary evil  of economic development that also occurred in early years in the industrial countries in europe , as epitomized by the  london fog  .
living with the so - called necessary evil has lasted for 30 years , if not more , in china .
the beneficial economic result ( yang ) from air - polluting industries is being replaced by the deleterious impact ( yin ) .
air pollution has become bad economically and has to be tackled as an economic issue .
the adverse public health impact of air pollution is well recognized and accepted based on published research . who has declared that air pollution is a carcinogen , . in this special issue , loomis et al . from the international agency for research on cancer ( iarc ) of who provide a review on the link between air pollution and cancer .
raaschou - nielsen et al . recently published a comprehensive investigation on the link between air pollution and cancer in 17 european cohorts , and in this issue , hoek et al .
although air pollution is an indisputable carcinogen for lung cancer based on a number of studies , the exact link and extent of the association in china have not been established because of a lack of data . although it is not necessary to prove a point that has been proven , much needs to be learned about the impact of air pollution . in an article by huang et al . in this issue
, the investigators comprehensively examine available cancer registry data and detailed air pollutant measurement data and provide an extensive analysis of the link between air pollution and cancer in china .
the goal of this special issue of the chinese journal of cancer is to bring the relationship between air pollution and cancer into focus and encourage international collaboration on this topic .
we hope this special issue will stimulate discussions and help identify important questions , such as those that follow here .
in addition to lung cancer , what other cancer types are caused by air pollution ? what genetic and epigenetic alterations are caused by different components of air pollution ?
for example , are lung cancers in non - smoker chinese women characterized by frequent mutations of epidermal growth factor receptor ( egfr ) caused by air pollution ? in vitro and animal model studies are needed to identify specific and targetable mutational changes associated with air pollution that may have a therapeutic solution .
old - generation technologies that emit pollutant fumes in steel- and cement - producing industries must be replaced with modern and clean technologies .
a national cancer registry has to be established to monitor cancer incidence and trends in a timely fashion .
personal devices that monitor exposure to pollution and easy - to - use , over - the - counter assays should also be developed as personalized medicine .
pharmacogenomics should be extended to the arena of air pollution to fully understand the genetic and epigenetic impact of pollutants on the human genome and epigenome .
clinical trials should be initiated to match mutational events with specific silver bullets as therapeutic solutions .
these are some emerging medical challenges to humanity in this era of living with cancer and with causes of cancer .
great opportunities exist for international collaborations to share information on environmental pollutions including air , water , and land pollutions and on cutting - edge technologies to reduce global environmental pollution levels . like the war on cancer
it might have been a necessary evil for the last 30 years in china , but it is an evil , nonetheless , that must be tackled urgently before it causes a major public health catastrophe .
this is certainly easier said than done because of the multitude of political , economic , scientific , and technological issues involved .
however , like charles caleb colton said :  evils in the journey of life are like the hills which alarm travelers on the road . both appear great at a distance , but when we approach them we find they are far less insurmountable than we had conceived . 
 once considered a taboo topic or stigma , cancer is the number one public health enemy in the world . 
 once a product of an almost untouchable industry , tobacco is indisputably recognized as a major cause of cancer and a target for anticancer efforts . with the emergence of new economic powers in the world , especially in highly populated countries such as china , 
 air pollution has rapidly emerged as a smoking gun for cancer and has become a hot topic for public health debate because of the complex political , economic , scientific , and technologic issues surrounding the air pollution problem . 
 this editorial and the referred articles published in this special issue of the chinese journal of cancer discuss these fundamental questions . 
 does air pollution cause a wide spectrum of cancers ? should air pollution be considered a necessary evil accompanying economic transformation in developing countries ? is an explosion of cancer incidence coming to china and how soon will it arrive ? what must be done to prevent this possible human catastrophe ? 
 finally , the approaches for air pollution control are also discussed . 
Air Pollution Control Requires the Political Will
Air Pollution Control Requires Shrewd Economic Consideration
Air Pollution Control Needs Vigorous Scientific Research
Air Pollution Control Needs Technological Advancement