Potential Residential Exposure to Toxics Release Inventory Chemicals during Pregnancy and Childhood Brain Cancer

BACKGROUND: Although the susceptibility of the developing fetus to various chemical exposures is well documented, the role of environmental chemicals in childhood brain cancer etiology is not well understood. OBJECTIVES: We aimed to evaluate whether mothers of childhood brain cancer cases had greater potential residential exposure to Toxics Release Inventory (TRI) chemicals than control mothers during pregnancy. METHODS: We included 382 brain cancer cases diagnosed at < 10 years of age from 1993 through 1997 who were identified from four statewide cancer registries. One-to-one matched controls were selected by random-digit dialing. Computer-assisted telephone interviews were conducted. Using residential history of mothers during pregnancy, we measured proximity to TRI facilities and exposure index, including mass and chemicals released. We calculated odds ratios (ORs) and 95% confidence intervals (CIs) using conditional logistic regression to estimate brain cancer risk associated with TRI chemicals. RESULTS: Increased risk was observed for mothers living within 1 mi of a TRI facility (OR = 1.66; 95% CI, 1.11–2.48) and living within 1 mi of a facility releasing carcinogens (OR = 1.72; 95% CI, 1.05–2.82) for having children diagnosed with brain cancer before 5 years of age, compared to living > 1 mi from a facility. Taking into account the mass and toxicity of chemical releases, we found a nonsignificant increase in risk (OR = 1.25; 95% CI, 0.67–2.34) comparing those with the lowest versus highest exposure index. CONCLUSIONS: Risk of childhood brain cancers may be associated with living near a TRI facility; however, this is an exploratory study and further studies are needed

The association between antihypertensive drugs and glioma

We pursued an association between hypertension and gliomas by investigating whether antihypertensive drugs (AHD) are associated with an increased glioma risk by a population-based nested case–control study using the PHARMO database; this links dispensing records of prescription drugs to hospital discharge data on an individual basis. Pathological data were derived from the Dutch nationwide registry of histo- and cytopathology. A total of 306 glioma cases incident between 1997 and 2003 were matched to 1108 controls for year of birth, sex, geographical region and duration of follow-up. Exposure was defined as cumulative duration of AHD use and, in an alternative analysis, as cumulative dose. We estimated the magnitude of the association with conditional logistic regression analysis. Cumulative use of any AHD for more than 6 months was associated with an increased risk of glioma (OR 1.45; 95% CI 1.03–2.04). After stratification for different groups of AHD, no significantly increased risk of glioma was found for any class of AHD. After excluding a latency period of 3 years before the date of diagnosis, no association was found. In conclusion, the use of AHD seems to be associated with an increased risk of glioma, but this is probably not causal

Exposure to Pesticides and the Risk of Childhood Brain Tumors

Purpose Previous research has suggested positive associations between parental or childhood exposure to pesticides and risk of childhood brain tumors (CBT). This Australian case–control study of CBT investigated whether exposures to pesticides before pregnancy, during pregnancy and duringchildhood, were associated with an increased risk.Methods Cases were recruited from 10 pediatric oncology centers, and controls by random-digit dialing, frequency matched on age, sex, and State of residence. Exposure data were collected by written questionnaires and telephone interviews. Data were analyzed by unconditional logistic regression.Results The odds ratios (ORs) for professional pest control treatments in the home in the year before the index pregnancy, during the pregnancy, and after the child’s birth were 1.54 (95 % confidence interval (CI): 1.07, 2.22), 1.52 (95 % CI: 0.99, 2.34) and 1.04 (95 % CI: 0.75, 1.43), respectively. ORs for treatments exclusively before pregnancy and during pregnancy were 1.90 (95 % CI: 1.08, 3.36) and 1.02 (95 % CI: 0.35, 3.00), respectively. The OR for the father being home during the treatment was 1.79(95 % CI: 0.85, 3.80). The OR for paternal occupational exposure in the year before the child’s conception was 1.36 (95 % CI: 0.66, 2.80). ORs for prenatal home pesticide exposure were elevated for low- and high-grade gliomas; effect estimates for other CBT subtypes varied and lacked precision.Conclusions These results suggest that preconception pesticide exposure, and possibly exposure during pregnancy, is associated with an increased CBT risk. It may be advisable for both parents to avoid pesticide exposure during this time

Brain tumors in children and adolescents and exposure to animals and farm life : a multicenter case-control study (CEFALO)

OBJECTIVES: The etiology of brain tumors in children and adolescents is largely unknown, and very few environmental risk factors have been identified. The aim of this study was to examine the relationship between pre- or postnatal animal contacts or farm exposures and the risk of childhood brain tumors (CBTs), since infectious agents may pose a risk factor and a proposed mechanism is transferral of infectious agents from animals to humans. METHODS: The case-control study conducted in Denmark, Norway, Sweden, and Switzerland included brain tumor cases diagnosed from 2004 to 2008 aged 7-19 years at diagnosis. Three hundred and fifty-two cases (83 % participation rate) were matched to 646 population-based controls (71 % participation rate). Conditional logistic regression was used to estimate odds ratios. RESULTS: Maternal farm residence during pregnancy was inversely related to all CBTs combined (adjusted odds ratio (aOR) = 0.40, 95 % confidence interval (CI) = 0.19-0.88), as was the child's farm residence but not statistically significantly so (aOR = 0.57, 95 % CI = 0.28-1.17). Exposure to animals was in general not related to CBT risk except postnatal contact with birds showing reduced aORs of all CBTs (0.67, 95 % CI = 0.46-0.97) and primitive neuroectodermal tumor (0.28, 95 % CI = 0.10-0.83). Sensitivity analyses focusing on early exposure of the child did not change the associations observed for the entire exposure period with the exception of exposure to goats and sheep which was associated with reduced risks of both all CBTs (aOR = 0.48, 95 % CI = 0.24-0.97) and astrocytomas (aOR = 0.29, 95 % CI = 0.10-0.87). CONCLUSION: Altogether, our data indicate an inverse association between the mother during pregnancy or the child living on a farm and CBT risk, which contrasts with the existing literature and merits further attention. With respect to exposure to animals, we did not observe any systematic pattern. This suggests that a potential protective effect of farm residence is mediated by some other factor than animal contac