[Study on the ecological association between natural radioactivity and childhood leukemia in Guangdong province].
OBJECTIVE
This study was undertaken to evaluate the ecological association between terrestrial natural radionuclide, indoor radon concentration, natural radioactivity and leukemia incidence among children under 18 years of age.


METHODS
Data were gathered from the disease surveillance program and literature reading while software SPSS 13.0 was used to calculate the Spearman's correlation.


RESULTS
The incidence rates of childhood (0-18 year) leukemia showed significant differences in different places with the highest as 3.13/10(5) in Jiangmen area and the lowest as 0.42/10(5) in Maoming area. The incidence in Jiangmen was 7.45 times higher than that in Maoming. There was a rank correlation between the incidence of childhood leukemia and the mean concentrations of natural radio-nuclides in soil (226Ra and 232Th), with a positive correlation observed for overall leukemia (r(s) = 0.70, P = 0.011; r(s) = 0.66, P= 0.02 for 226 Ra and 232Th respectively) and acute lymphoblastic leukemia (ALL) (r(s) = 0.66, P = 0.019; r(s) = 0.64, P = 0.025 for 226 Ra and 232Th respectively). Associations between the incidence of childhood leukemia and the indoor gamma radiation dose rate, the total annual average effective dose equivalent from natural background radiationwere also analyzed (both r(s) = 0.59, P = 0.042).


CONCLUSIONS
The natural radioactivity was likely to be a causative factor for childhood leukemia in Guangdong.
Ma
Jin-Xiang
JX
Department of Preventive Medicine of Guangzhou Medical College, Guangzhou 510182, China.
Lei
Yi-Xiong
YX
Ye
Tie-Zhen
TZ
D000293:Adolescent; D000396:Air Pollutants, Radioactive / Q000009:adverse effects; D002648:Child; D002675:Child, Preschool; D002681:China / Q000453:epidemiology; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007938:Leukemia / Q000453:epidemiology* / Q000209:etiology*; D008297:Male; D011834:Radiation Monitoring; D011886:Radon / Q000009:adverse effects; D012990:Soil Pollutants, Radioactive / Q000009:adverse effects
D000396:Air Pollutants, Radioactive; D012990:Soil Pollutants, Radioactive; D011886:Radon