Maternal Residential Proximity to Major Roadways and Pediatric Embryonal Tumors in Offspring

Abstract

The environmental determinants of pediatric embryonal tumors remain unclear. Because of the growing concern over the impact of exposures to traffic-related air pollution on pediatric cancer, we conducted a population-based study evaluating the impact of maternal residential proximity to major roadways on the risk of pediatric embryonal tumors in offspring. We identified children diagnosed with neuroblastoma, Wilms tumor, retinoblastoma, or hepatoblastoma at <5 years of age from the Texas Cancer Registry and selected unaffected controls from birth certificates. Two residential proximity measures were used: (1) distance to the nearest major roadway, and (2) within 500 m of a major roadway. Logistic regression was used to estimate the adjusted odds ratio (aOR) and 95% confidence interval (CI) for each proximity measure on pediatric embryonal tumors. The odds of an embryonal tumor were increased in children born to mothers living within 500 m of a major roadway (aOR = 1.24, 95% CI: 1.00, 1.54). This was consistent for most tumor subtypes, with the strongest associations observed for unilateral retinoblastoma (aOR = 2.57, 95% CI: 1.28, 5.15, for every kilometer closer the mother lived to the nearest major roadway). These findings contribute to the growing evidence that traffic-related air pollution may increase risk for certain pediatric tumors.

Outdoor air pollution and cancer: An overview of the current evidence and public health recommendations

“…138 A Texas study reported an adverse association of embryonal tumors in children whose mothers lived <500 meters from a major road during pregnancy compared with ≥500 meters (OR, 1.24; 95% CI, 1.00-1.54), with the strongest findings observed for unilateral retinoblastoma (OR, 1.68; 95% CI, 0.96-2.93). 139 In a study of more than 2 million Canadian children who were followed from birth to 4 years, PM 2.5 exposure during the first trimester had a significant adverse association with astrocytoma (HR per 4.0 μg/m 3 , 1.40; 95% CI, 1.05-1.86, n = 94), and first-trimester NO 2 had a significant adverse association with ALL (HR per 13.3 ppb,1.20; 95% CI, 1.02-1.41; n = 302). 140 Finally, a Utah study reported significant adverse PM 2.5 cancer mortality associations among pediatric patients with lymphoma and CNS tumors as well as among adolescent and young adult patients with CNS tumors, carcinomas, melanomas, breast cancers, and colorectal cancers.…”

Maternal Residential Proximity to Major Roadways and the Risk of Childhood Acute Leukemia: A Population-Based Case-Control Study in Texas, 1995–2011

“…Therefore, we were unable to assess shorter exposure distances in this study. However, there is support for analyses investigating 500 m buffers as done herein [19,31,71]. Future studies should put planning in place to consider smaller buffer regions.…”

“…The “low roadway density” category included mothers living outside the 500 m buffer radius from the nearest major roadway, while mothers residing within 500 m of a major roadway were defined as residing in an area with “medium roadway density” or “high roadway density” based on the total length of major roadway within the 500 m buffer. Consistent with previous studies [19,31], the cutoff between medium and high density (2.11 km) was determined using the median split of the distribution of roadway density among the control subjects living within 500 m of a major roadway.…”

Methodological approaches to the study of cancer risk in the vicinity of pollution sources: the experience of a population-based case–control study of childhood cancer

“…Epidemiological studies of childhood cancer in relation to proximity to pollution foci have reached great importance recently [22–27], and industrial registers of toxic substances as the E-PRTR provide a tool for the monitoring and surveillance of harmful effects of these industrial pollutants, some of them carcinogenic, on the human health. In this sense, our experience is being positive because our study is providing some epidemiological clues that residing in the vicinity of certain industrial and urban areas may be a risk factor for some types of childhood cancers.…”

“…With respect to proximity to environmental exposures and childhood renal tumors, the few studies focused on residential proximity to environmental pollution sources did not find associations in relation to hazardous waste sites [36] or major roadways [27]. However, some authors have found associations between children prenatally exposed to polycyclic aromatic hydrocarbons during the third trimester and risk of Wilms’s tumor (the main histologic type of childhood renal tumors) [37], something that could be related to our findings about this type of pollutant (see Table 6).…”