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

Abstract

Acute leukemia is the most common pediatric malignancy. Some studies suggest early-life exposures to air pollution increase risk of childhood leukemia. Therefore, we explored the association between maternal residential proximity to major roadways and risk of acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML). Information on cases with acute leukemia (n = 2030) was obtained for the period 1995–2011 from the Texas Cancer Registry. Birth certificate controls were frequency matched (10:1) on birth year (n = 20,300). Three residential proximity measures were assessed: (1) distance to nearest major roadway, (2) residence within 500 meters of a major roadway, and (3) roadway density. Multivariate logistic regression was used to generate adjusted odds ratios (aOR) and 95% confidence intervals (CI). Mothers who lived ≤500 meters to a major roadway were not more likely to have a child who developed ALL (OR = 1.03; 95% CI: 0.91–1.16) or AML (OR = 0.84; 95% CI: 0.64–1.11). Mothers who lived in areas characterized by high roadway density were not more likely to have children who developed ALL (OR = 1.06, 95% CI: 0.93–1.20) or AML (OR = 0.83, 95% CI: 0.61–1.13). Our results do not support the hypothesis that maternal proximity to major roadways is strongly associated with childhood acute leukemia. Future assessments evaluating the role of early-life exposure to environmental factors on acute leukemia risk should explore novel methods for directly measuring exposures during relevant periods of development.

Air pollution exposure at the residence and risk of childhood cancers in Denmark: A nationwide register-based case-control study

“…The two most recent and comprehensive meta-analyses, however, reported higher relative risks of leukemia related to benzene exposure [ 37 , 38 ]. A nationwide Swiss study recently showed an association between proximity of residence to highways and leukemia, [39] whereas an American case-control study did not show evidence of such an association [40] . A Canadian study found associations between maternal exposure to the mass concentration of particulate matter smaller than 2·5 µm (PM 2·5 ) in pregnancy and astrocytoma as well as between nitrogen dioxide (NO 2 ) and acute lymphoblastic leukemia (ALL) [41] .…”

Multiple air pollutants exposure and leukaemia incidence in Tehran, Iran from 2010 to 2016: a retrospective cohort study

“…In single-pollutant models, NO 2 and NO x were significantly associated with increased leukaemia incidence in model 1 (adjusted for age and gender) and also in model 2 (adjusted in addition for urban green space per capita) with IRR (95% CI) of model 2, respectively, 1. 35 (1.11-1.64) and 1.07 (1.03-1.11) per 10 ppb increase in pollutants. In model 3, after adjustment for age, gender, socioeconomic status and life expectancy, only NO X was significantly associated with increased leukaemia incidence with an IRR (95% CI) of 1.03 (1.003-1.06) per 10 ppb increase in NO x .…”

“…They indicated that mothers who lived closer than 500 m to a major roadway and mothers who lived in high roadway density areas were not more likely to have a child with ALL or AML. 35 Although many studies have shown a possible relation between air pollution and leukaemia, there is still a need for more high-quality studies with higher sample sizes, and better control of confounders.…”

“…However, Peckham-Gregory et al conducted a population-based case-control study in Texas to evaluate the association between maternal residential proximity to major roadways and developing ALL and AML in children, and reached different results. They indicated that mothers who lived closer than 500 m to a major roadway and mothers who lived in high roadway density areas were not more likely to have a child with ALL or AML 35…”

Environmental risk factors for pediatric acute leukemia: Methodology and early findings

“…It has also been observed that exposure to second-hand cigarette smoke of the parents also has associations with childhood leukemia[ 3 ] as well as prognostic value in ALL patients. [ 16 ] Pesticide,[ 17 ] chemicals,[ 18 ] parental occupation,[ 19 ] and residential proximity to gasoline stations or roads with heavy traffic[ 20 21 ] have been weakly or controversially associated with childhood leukemia. Studies have also shown that indoor chemical air pollution creates a two-fold increase in ALL when comparing those with the highest and lowest amounts of pollution.…”