TITLE:
Linking of Environmental and Health Indicators by Neural Networks: Case of Breast Cancer Mortality, Slovak Republic
AUTHORS:
Stanislav Rapant, Mária Letkovičová, Veronika Cvečková, Andrej Ďurža, Katarína Fajčíková, Hana Zach
KEYWORDS:
Neural Network; Breast Cancer Mortality; Environmental Indicators; Soil; Groundwater; Slovak Republic
JOURNAL NAME:
Open Journal of Geology,
Vol.3 No.2,
April
29,
2013
ABSTRACT: This study deals with the analysis of
relationship between 67 environmental indicators in geological environment and
breast cancer mortality in Slovakia. Primary data comprises a database of 67
environmental indicators for groundwater and soils as a mean value for every
Slovak municipality and the data on relative mortality from breast cancer for
Slovak municipalities (about 2900) collected for the period of 22 years. The
training neural network was used as a mathematical model for data analysis. The
top 200 networks have identified 12 environmental indicators (8 for soils: pHKCl,
carbonates, Ca, Mg, Na, Co, Sr and 4 for groundwater: Ba, SiO2, Zn,
Fe) with high rate of influence. As the most influential environmental indicator
was identified pHKCl in soil that should be within the range of
acids, definitely under the neutral point. Most of environmental indicators
were unambiguously identified as negative (Mg, Ca, Sr, carbonates, Ba, SiO2,
Zn and Fe). These indicators should be at the lowest level of their
concentration in related geological component. Three environmental indicators,
Ce, Na and Co had parabolic function where certain essential concentration
levels of these elements are presumed with protective effect on human health.
For all influential indicators limit values with respect to the lowest
mortality were proposed. The verification of achieved results was performed
through regressive model of breast cancer mortality for 12 calculated
influential environmental indicators for all municipalities in the Slovak
Republic. The revealed difference between real mortality levels and the model
values was found for 6 environmental indicators (pHKCl, Mg, Ca, Sr,
Ba, Zn). Each executed limit has decreased breast cancer mortality for about
0.79 cases per 100,000 inhabitants.