OBJECTIVETo study the types of soil and vegetation as well as soil organic carbon densities (SOCD) from high and low risk areas of esophageal cancer (EC) in China.

METHODSDatabase from EC mortality survey in 1990-1992 in China was established in Excel. Digital polygon maps of study areas were created in ArcGIS 9.1 and linked with the database. The types of soil and vegetation from sampling areas were extracted from digital maps of soil type, vegetation type while the map of distribution on EC mortality was using the polygon overlay analysis. SOCD at depths of 100 cm and 20 cm of these areas were calculated, and spearman correlation analysis was used to evaluate the relationship between EC mortality and SOCD.

RESULTSThe types of soil and vegetation and related distributions from high and low risk areas of EC in China showed obvious differences. There were both negative correlations between EC mortality and SOCD at depths of 100 cm and 20 cm. The correlation coefficients for man were -0.504 and -0.575 (P = 0.004, 0.001 respectively), and that for woman were -0.487 and -0.526 (P = 0.003, 0.001 respectively).

CONCLUSIONMortality rate of esophageal cancer might correlate to SOCD, the types of soil and vegetation which called for further studies.

China ; epidemiology ; Environmental Monitoring ; methods ; Epidemiological Monitoring ; Esophageal Neoplasms ; epidemiology ; Geographic Information Systems ; Geography ; Humans ; Plants ; Soil ; analysis

PURPOSE: This study aims to assess the association of sunlight exposure with breast cancer risk, measured by the breast density assessed from Tabar's mammographic pattern in Chinese women. METHODS: A total of 676 premenopausal women were recruited to participate in this study, in which 650 completed a validated sunlight exposure questionnaire via telephone. The mammograms were classified according to Tabar's classification for parenchyma, and patterns IV & V and I, II & III indicated respectively high and low risk mammographic patterns for breast cancer. The odds ratios (OR) and 95% confidence intervals (CIs) for sun exposure-related variables were estimated using unconditional logistic regression with adjustment for potential confounders. RESULTS: Among 646 participants, women with high breast cancer risk (Tabar's patterns IV &V) had less hours spent in the sun than those with low risk (I, II & III) at any age stage. A higher level of sunlight exposure was associated with a significantly lower risk having high risk Tabar's pattern. Women aged 40 to 44 years who were in the highest tertile of lifetime total hours spent in the sun had a multi-adjusted OR of 0.41 (95% CI, 0.18-0.92; p for trend=0.03) compared with those in the lowest tertile (>2.19 hr/day vs. <1.32 hr/day). For hours spent in the sun across the ages of 6 to 12 years, the comparable OR was 0.37 (95% CI, 0.15-0.91; p for trend=0.03). CONCLUSION: These findings suggest that higher sunlight exposure is related to a lower risk of having high risk breast density pattern in premenopausal women. Our results also suggest the most relevant period of exposure is during earlier life.
Aged ; Asian Continental Ancestry Group ; Breast ; Breast Neoplasms ; Female ; Humans ; Logistic Models ; Mammary Glands, Human ; Odds Ratio ; Solar System ; Sunlight ; Telephone ; Vitamin D ; Surveys and Questionnaires