Reynolds Peggy, Von Behren Julie, Gunier Robert B, Goldberg Debbie E, Hertz Andrew
California Department of Health Services, Environmental Health Investigations Branch, Oakland, California 94612, USA.
Epidemiology. 2004 Jan;15(1):6-12. doi: 10.1097/01.ede.0000101749.28283.de.
Motor vehicle emissions are a major source of air pollution in California. Past studies have suggested that traffic-related exposures can increase the risk of childhood cancer, particularly leukemia.
From California's statewide, population-based cancer registry, we identified cancers diagnosed in children younger than 5 years of age between 1988 and 1997. We matched these cases to California birth certificates. For each case, we randomly selected 2 control birth certificates, matched by birth date and sex. For each mother's residential address at the time of her child's birth, we calculated road density by summing the length of all roads within a 500-foot radius of the residence. Traffic density was based on road lengths and vehicle traffic counts for highways and major roads.
The distributions of road and traffic density values were very similar for the 4369 cases and 8730 matched control subjects. For all cancer sites combined, the odds ratio (OR) for the highest road density exposure category, compared with the lowest, was 0.87 (95% confidence interval [CI] = 0.75-1.00). For all sites combined and for leukemia, the ORs were also below 1.0 for the highest traffic density exposure category (0.92 for both). For central nervous system tumors, the OR was 1.22 (CI = 0.87-1.70).
In a large study with good power, we found no increased cancer risk among offspring of mothers living in high traffic density areas for all cancer sites or leukemia.
机动车排放是加利福尼亚空气污染的主要来源。过去的研究表明，与交通相关的暴露会增加儿童患癌症的风险，尤其是白血病。
从加利福尼亚州基于人群的全州癌症登记处，我们确定了1988年至1997年间5岁以下儿童被诊断出的癌症。我们将这些病例与加利福尼亚出生证明进行匹配。对于每个病例，我们随机选择2份对照出生证明，按出生日期和性别进行匹配。对于每个母亲在其孩子出生时的居住地址，我们通过计算居住地址半径500英尺内所有道路的长度总和来计算道路密度。交通密度基于高速公路和主要道路的道路长度和车辆交通流量。
4369例病例和8730名匹配的对照受试者的道路和交通密度值分布非常相似。对于所有合并的癌症部位，道路密度最高暴露类别与最低暴露类别相比的优势比（OR）为0.87（95%置信区间[CI]=0.75 - 1.00）。对于所有合并部位以及白血病而言，交通密度最高暴露类别（两者均为0.92）的OR也低于1.0。对于中枢神经系统肿瘤，OR为1.22（CI = 0.87 - 1.70）。
在一项具有良好效能的大型研究中，我们发现居住在高交通密度地区的母亲的后代在所有癌症部位或白血病方面患癌风险没有增加。
