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The correlations of age-adjusted incidences of various forms of cancer with the geochemical composition of well water and other forms of groundwater in northern Finland have been studied using standard statistical methods. Available geochemical maps showing the hardness of the water and its uranium, iron and nitrate content and maps depicting the areal distribution of the incidences of ten forms of cancer, were decoded point by point to numerical concentration or incidence values by placing a transparent sheet carrying a regular rectangular grid over each. The grid covering the north of Finland (north of 65 ° N latitude) comprised 261 observation points distributed at regular intervals of about 25 km on the ground.The calculated Spearman product-moment and rank correlation coefficients between the geochemical and medical variables suggest that a strong, statistically significant (p<0.001) positive correlation prevails between the hardness of the water and several forms of cancer, especially total cancer (all forms of cancer combined) in the female population (r = 0.66). On the other hand, iron and, somewhat surprisingly, nitrates, which are commonly thought to promote cancer, show a low degree of correlation with the forms of cancer studied. Also, contrary to expectation, a negative correlation between most forms of cancer with groundwater uranium is indicated, a result which, because of its unexpectedness, calls for further research work based on larger data sets before a conclusion can be drawn that it can be interpreted as an implication of a trend that an appropriate level of uranium in the groundwater and the resulting gentle dose of natural radioactive irradiation can help to prevent the early development of cancer in human tissues and cells.The positive correlation between water hardness and most forms of cancer studied suggests that hard drinking water may be an initiator and promoter of cancer, although it is admitted that the establishment of a positive correlation between the geochemical and medical variables does not necessarily prove a cause-and-effect relationship between them.

In Finland, where mortality rates of cardiovascular diseases are as a rule among the highest in the world, significant areal differences in these figures are encountered especially between the eastern and western parts of the country. To test the hypothesis that these differences,( the reason of which has long been a subject for a lively debate in Finland), may result from geochemical factors such as variations in the hardness or calcium or magnesium content of well water a correlation analysis was carried out in which the geochemical properties in each of the country's individual administrative districts, or communes (444 in all, excluding Åland) were compared with the percentage of heart diseases among the causes of death from diseases in 1991. The results show a poor or extremely low correlation nation-wide (r ranging from -0.039 to +0.045), indicating a virtual absence of any causal relationship. On the other hand, taken pairwise, the extreme western and eastern provinces, Vaasa andNorthern Karelia, show marked differences both in their geochemical and mortality data, the percentage of deaths caused by cardiovascular diseases being markedly lower in the province of Vaasa, where the hardness and the magnesium content of well water (but not the calcium content) are significantly higher (p < 0.001 and 0.002 respectively). This inverse relationship is in line with the supposition that in addition to other factors, geochemical differences may have an effect on mortality.

The course of events as well as the chemical changes associated with the alteration of clinopyroxenes to uralite have been studied from diabases in Kuusamo, Finland. The uralitization takes place in several phases starting from the intercumulus spaces, where latemagmatic fluids cause an increase in iron and titanium in the pyroxene as a first phase of alteration. During the second phase the pyroxene is altered to actinolitic amphibole which appears as isolated flakes within the pyroxene, later the entire pyroxene crystal becomes filled with colourless amphibole. At this stage Fe, Ti, Al and K and Na are introduced internally from the rock-mass itself into the altering mineral. Some Ca is removed simultaneously. Finally, the amphibole changes into a green hornblende with additional introduction of the above elements. During the last phase the crystal boundaries of the original pyroxene are exceeded and the amphibole overflows from the pyroxene crystal spaces at the expense of the adjoining plagioclase that participates in the reaction. The density of the uralitized rock is somewhat lower than that of an unaltered counterpart. It is postulated that some silica is removed during the process to account for the drop in the density.

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