Yang Hongxi, Li Shu, Sun Li, Zhang Xinyu, Hou Jie, Wang Yaogang
School of Public Health, Tianjin Medical University, Tianjin, China.
School of Nursing, Tianjin Medical University, Tianjin, China.
JMIR Public Health Surveill. 2017 Oct 3;3(4):e64. doi: 10.2196/publichealth.8078.
In October 2013, the International Agency for Research on Cancer classified the particulate matter from outdoor air pollution as a group 1 carcinogen and declared that particulate matter can cause lung cancer. Fine particular matter (PM) pollution is becoming a serious public health concern in urban areas of China. It is essential to emphasize the importance of the public's awareness and knowledge of modifiable risk factors of lung cancer for prevention.
The objective of our study was to explore the public's awareness of the association of PM with lung cancer risk in China by analyzing the relationship between the daily PM concentration and searches for the term "lung cancer" on an Internet big data platform, Baidu.
We collected daily PM concentration data and daily Baidu Index data in 31 Chinese capital cities from January 1, 2014 to December 31, 2016. We used Spearman correlation analysis to explore correlations between the daily Baidu Index for lung cancer searches and the daily average PM concentration. Granger causality test was used to analyze the causal relationship between the 2 time-series variables.
In 23 of the 31 cities, the pairwise correlation coefficients (Spearman rho) between the daily Baidu Index for lung cancer searches and the daily average PM concentration were positive and statistically significant (P<.05). However, the correlation between the daily Baidu Index for lung cancer searches and the daily average PM concentration was poor (all r<.1). Results of Granger causality testing illustrated that there was no unidirectional causality from the daily PM concentration to the daily Baidu Index for lung cancer searches, which was statistically significant at the 5% level for each city.
The daily average PM concentration had a weak positive impact on the daily search interest for lung cancer on the Baidu search engine. Well-designed awareness campaigns are needed to enhance the general public's awareness of the association of PM with lung cancer risk, to lead the public to seek more information about PM and its hazards, and to cope with their environment and its risks appropriately.
2013年10月，国际癌症研究机构将室外空气污染中的颗粒物列为1类致癌物，并宣称颗粒物可导致肺癌。细颗粒物（PM）污染正成为中国城市地区严重的公共卫生问题。强调公众对肺癌可改变风险因素的认识和了解对于预防的重要性至关重要。
我们研究的目的是通过分析每日PM浓度与互联网大数据平台百度上“肺癌”搜索词之间的关系，探讨中国公众对PM与肺癌风险关联的认识。
我们收集了2014年1月1日至2016年12月31日中国31个省会城市的每日PM浓度数据和每日百度指数数据。我们使用Spearman相关分析来探讨肺癌搜索的每日百度指数与每日平均PM浓度之间的相关性。采用格兰杰因果检验分析这两个时间序列变量之间的因果关系。
在31个城市中的23个城市，肺癌搜索的每日百度指数与每日平均PM浓度之间的成对相关系数（Spearman rho）为正且具有统计学意义（P<0.05）。然而，肺癌搜索的每日百度指数与每日平均PM浓度之间的相关性较差（所有r<0.1）。格兰杰因果检验结果表明，从每日PM浓度到肺癌搜索的每日百度指数不存在单向因果关系，每个城市在5%水平上具有统计学意义。
每日平均PM浓度对百度搜索引擎上肺癌的每日搜索兴趣有微弱的正向影响。需要精心设计提高认识的活动，以增强公众对PM与肺癌风险关联的认识，引导公众寻求更多关于PM及其危害的信息，并适当应对其环境及其风险。
