Epidemiological study (observational study)

Increased risk of childhood acute lymphoblastic leukemia (ALL) by prenatal and postnatal exposure to high voltage power lines: a case control study in Isfahan, Iran. epidem.

By: Tabrizi MM, Bidgoli SA

Published in: Asian Pac J Cancer Prev 2015; 16 (6): 2347-2350

Aim of study (acc. to author)

A case-control study was conducted in Iran to investigate the role of prenatal and postnatal exposure to high voltage power lines and other risk factors on the incidence of childhood acute lymphoblastic leukemia.

Further details

Remark EMF-Portal: Number of cases and controls as well as study results and whole chapters of this publication are identical in the publication by Tabrizi and Hosseini (2015). It is unclear whether this is a replication study with the same results or two studies conducted in two different cities with the same results.
Details of exposure assessment are missing in this publication. It is not stated how 'living near high voltage power lines' is defined and how the exposure to power lines was classified into 'yes' or 'no'.

Endpoint/type of risk estimation

childhood leukemia: acute lymphoblastic leukemia

Type of risk estimation:

incidence

(odds ratio (OR))

Exposure

- 50/60 Hz
- magnetic field
- also other exposures without EMF
- power transmission line
- residential

Assessment

questionnaire: living near high voltage power lines, using mobile phones, computers, microwave and all indoor electrically charged objects

Exposure groups

Group	Description
Reference group 1	prenatal exposure to power lines: no
Group 2	prenatal exposure to power lines: yes
Reference group 3	postnatal exposure to power lines: no
Group 4	postnatal exposure to power lines: yes

Population

Group:
- children
- children in utero
Age: 0–11 years
Observation period: 2013 - 2014
Study location: Iran (Isfahan)

Case group

Exclusion criteria: lack of access to the parents, birth and living out of Isfahan, having moderate and higher socioeconomic status

Control group

Matching:
- area
- 5-year age group

Study size

	Cases	Controls
Evaluable	22	100

Statistical analysis method:

Chi-square test
t-test, Cochrane-Mantel-Haenszel test

Conclusion (acc. to author)

Overall, 4 out of 22 (18.8%) of children with acute lymphoblastic leukemia and 3 out of 100 control children were exposed to high voltage power lines. As the population study was from low socioeconomic status, use of mobile phones, computers and microwave ovens was negligible.
Prenatal and childhood exposure to high voltage power lines was considered as the most important environmental risk factors of acute lymphoblastic leukemia (OR 3.65, CI 1.69-7.88).
The authors concluded that prenatal and postnatal exposure to high voltage power lines and living in pollutant regions as well as familial history of leukemia and parental occupational exposure to chemicals and radiation could be described as risk factors of childhood acute lymphoblastic leukemia for the first time in a low socioeconomic status Iranian population.

Limitations (acc. to author)

The results are based on low numbers.

Comments on this article

Dechent D et al. (2016): Re: Role of Electromagnetic Field Exposure in Childhood Acute Lymphoblastic Leukemia and No Impact of Urinary Alpha- Amylase - a Case Control Study in Tehran, Iran.

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