# Causes of Childhood Cancer: A Literature Review (2014–2021)—Part 3: Environmental and Occupational Factors

## TL;DR

This paper reviews environmental factors linked to childhood cancer, highlighting risks like traffic pollution and pesticides to guide prevention efforts.

## Contribution

The paper consolidates recent evidence on environmental and occupational factors associated with childhood cancer for targeted prevention strategies.

## Key findings

- Strong evidence links leukemia to traffic pollution, indoor paint, pesticides, and benzene exposure.
- Brain cancer is strongly associated with residential and agricultural pesticide exposure.
- Mixed evidence exists for links between leukemia and EMFs or ionizing radiation.

## Abstract

Childhood cancer is a significant public health concern with increasing rates over decades suggesting that environmental factors may contribute to this trend. We reviewed studies published between 2014 and 2021 that examined childhood exposure to air pollution and radiation, as well as parental environmental and occupational exposures before conception or during pregnancy, in relation to childhood cancer. Strong evidence was found for associations between leukemia and exposures to traffic pollution, indoor paint, residential pesticides, and occupational/nonoccupational benzene, and between brain cancer and exposures to residential pesticides and occupational agricultural pesticides. There was mixed evidence of associations between leukemia and electromagnetic fields (EMFs), and ionizing radiation from radon or nuclear power plants. This review consolidates knowledge of environmental factors associated with childhood cancer to inform targeted prevention strategies.

Purpose: To achieve a better understanding of the environmental factors that contribute to childhood cancers, so as to inform future prevention efforts. Methods: We conducted a comprehensive review of epidemiological studies on environmental risk factors and childhood cancer, which was published between January 2014 and March 2021. Potential exposure sources presented in this review include air pollution, radiation, and parental occupational exposures. We considered exposures during childhood and parental exposures occurring before the child’s conception and during pregnancy in relation to all types of childhood cancer. Results: Aggregated evidence is strong for associations between leukemia and parental/child exposure to traffic pollution, indoor paints, residential pesticides, and parental occupational/nonoccupational exposure to benzene. Evidence is also strong for associations between brain cancer and residential pesticides and parental occupational exposure to agricultural pesticides. Evidence of associations between leukemia and ionizing radiation from radon and nuclear power plants remains mixed, as does evidence of a link between electromagnetic fields (EMFs) and childhood leukemia. Conclusions: Clear associations have been demonstrated between childhood cancer and environmental factors, including parent/child exposure to traffic pollution, occupational/nonoccupational benzene, indoor paints, residential pesticides, and parental occupational exposure to agricultural pesticides. These associations can be used to inform further study of interventions and public health campaigns to reduce risk.