| Summary: | 碩士 === 國立成功大學 === 環境醫學研究所 === 97 === Background
The health effect of radiofrequency has been a public concern for years. To improve the quality of weather forecasting, the Center Weather Bureau set up four Doppler radar stations in Taiwan in 2002. The weather radar disc moves in circles, transmits short pulses of electromagnetic waves, and listens for the reflected signals. The frequency of the radar system stations is 2836MHz, within the radio-frequency range of 300Hz to 300GHz. In order to assess the health effects of radiofrequency exposures form weather radar system, we conducted this study to evaluate the associations between weather radar system and the mortality or neoplasm incidence of the residents living in the two areas (Chi-Guw as Area I and Hualien as Area II) and two villages locating in Area I where the radar stations were
located.
Method
The all-cause mortality and neoplasm incidence of residents nears the radar stations were studied over the period 1997-2006. We compared the data between five years before and five years after the weather radar system was established. We calculated the age-standardized mortality ratio (SMR) method by dividing the number of cases observed in the study period by the expected number of cases (the number of cases observed in the five-year period before 2002). The total number of expected deaths was summed across all age categories. For comparing the mortality and incidence rates between the early, we calculated the standardized mortality ratios (SMRs) and standardized incidence ratios (SIRs) using the mortality and incidence rates observed in the five-year period before the establishment of the radar station as the reference. We considered two years as the latent
period.
Result:
The SMR of the all malignant neoplasm combined mortality was 1.06 (p=0.40) in Area I, 1.01 (p=0.80) in Area II, and 0.97 (p<0.001) in Taiwan. The SMR of the non-ionizing radiation related malignant neoplasm combined mortality was 1.08 (p=0.97) in Area I, 0.65 (p=0.11) in Area II, and 1.01 (p=0.73) in Taiwan. The SMR of all leukemia combined mortality was 1.49 (p=0.35) in Area I, 0.68 (p=0.26) in Area II, and 1.02 (p=0.44) in Taiwan. The SIR of the all neoplasm combined was 1.28 (p<0.01) in Area I, 1.02 (p=0.39) in Area II, and 1.04 (p<0.01) in Taiwan as a whole. The SIR of the non-ionizing radiation related malignant neoplasm combined was 1.66 (p=0.18) in Area I, 0.95 (p=0.91) in Area II, and 1.16 (p<0.01) in Taiwan. The SIR of the all leukemia combined was 2.59 (p=0.01) in Area I, 1.01 (p=0.90) in Area II, and 1.34 (p<0.01) in Taiwan. The SMR of the all malignant neoplasm combined mortality was 1.91 (p=0.10) in village I, 0.65 (p=0.10) in village II；<7> The SRR of the all malignant neoplasm combined mortality five years before was 1.251 (95% CI : 1.119-1.398) in area I, 0.998 (95% CI : 0.932-1.069) in area II，1 in Taiwan；<8> The SRR of the all malignant neoplasm combined mortality five years after was 1.273 (95% CI : 1.146-1.414) in area I, 0.965 (95% CI : 0.903-1.031) in area II, 1 in Taiwan；<9> The SRR of the non-ionizing radiation related malignant neoplasm combined mortality five years before was 1.503 (95% CI : 0.826-2.734) in area I, 0.924 (95% CI :0.635-1.343) in area II，1 in Taiwan；<10>The SRR of the non-ionizing radiation related malignant neoplasm combined mortality five years after was 1.295 (95% CI : 0.712-2.354) in area I , 1.065 (95% CI :=0.758-1.495) in area II，1 in Taiwan；<11> The SRR of all leukemia combined mortality five years before was 1.599 (95% CI : 0.768-3.332) in area I, 0.959 (95% CI :0.608-1.511) in area II，1 in Taiwan；<12> The SRR of all leukemia combined mortality five years after was 1.959 (95% CI : 1.078-3.563) in area I, 1.169 (95% CI :0.786-1.738) in area II，1 in Taiwan；<13> The SRR of the all neoplasm combined incidence five years before was SRR: 0.946 (95% CI : 0.877-1.020) in area I, 1.021 (95% CI : 0.981-1.063) in area II，1 in Taiwan；<14> The SRR of the all neoplasm combined incidence five years after 1.093 (95% CI : 1.020-1.170) in area I, 1.001 (95% CI : 0.963-1.040) in area II，1 in Taiwan；<15> The SRR of the non-ionizing radiation related malignant neoplasm combined incidence five years before was 1.179 (95% CI : 0.614-2.265) in area I, 1.133 (95% CI : 0.818-1.569) in area II，1 in Taiwan；<16> The SRR of the non-ionizing radiation related malignant neoplasm combined incidence five years after was 0.903 (95% CI : 0.485-1.680) in area I, 1.162 (95% CI : 0.869-1.555) in area II，1 in Taiwan；<17> The SRR of the all leukemia combined incidence five years before was 1.398 (95% CI : 0.640-3.052) in area I, 1.145 (95% CI : 0.757-1.732) in area II，1 in Taiwan；<18> The SRR of the all leukemia combined incidence five years after was 1.228 (95% CI : 0.644-2.342) in area I, 1.119 (95% CI : 0.785-1.596) in area II，1 in Taiwan； <19> The SRR of the all malignant neoplasm combined mortality five years before was 1.020 (95% CI : 0.456-2.280) in village I, 1.707 (95% CI : 1.230-2.368) in village II，1 in Taiwan；<20> The SRR of the all malignant neoplasm combined mortality five years after was 1.725 (95% CI : 0.925-3.217) in village
I, 1.052 (95% CI : 0.706-1.567) in village II，1 in Taiwan.
Conclusion:
We found no consistent increase in the mortality and incidence of all malignant neoplasm combined or leukemia in residents living in areas with radar station (Areas I、II and two villages). The study was designed as a ecological study, so it can’t determine the causal correlation between radar staion and personal health effect. The correlations between the morality or incidence of the non-ionizing radiation related malignant neoplasm and distance from the radar stations should be evaluated in the future study.
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