It is estimated
60% to 80% of all cancers are environmental in origin.
(1) There is a growing consensus that the majority of cancers are caused
by chemical carcinogens in the environment, and hence, ultimately
preventable. Several studies have demonstrated the presence of chemical
carcinogens in surface, ground water and municipally treated drinking
water. In addition, trihalomethanes (THM’s) can actually be produced
during the chlorine treatment of our drinking water.
In short, the amount of chemical compounds discharged in our water,
directly or indirectly is staggering. "Over 2100 organic and
inorganic drinking water contaminants have been identified in U.S.
drinking water supplies since 1974. Out of these 2100, 190 of the
contaminants have confirmed adverse health effects, whether carcinogens,
mutagens, teratogens or toxic." (2)
Even with the EPA drinking water standards, we cannot be assured, that
the tap water we are drinking is not going to weaken our immune system or
lead to cancer. Many cancer causing agents take twenty to thirty years
before the effects show up. Each of us is metabolically different and
reacts to carcinogenic agents in a unique way. Epstein sums it up,
‘There is no threshold for chemical carcinogens."
Information on a variety of carcinogenic agents in drinking water:
fluoridation, chlorinating and asbestos will be represented later.
However, before looking at these, there is some fascinating research based
on positive substances in drinking water that actually can help protect us
from cancer. This research centers on four factors: total dissolved solids
(TDS), hardness, pH and silica.
Burton and Cornhill analyzed the drinking water in 100 largest cities
in the United States. They found a 10% to 25% reduction in the amount of
cancer deaths if the drinking water contained a moderately high level of
TDS (around 300 mg/L) if the water was hard, if the water had an alkaline
pH (above 7.0) and if the water had 15 mg/L of silica. (3) (4)
Sauer also found a correlation between silica and cancer. Namely, the
more silica the less cancer. In addition, he also uncovered that when the
water was hard there was less cancer. Therefore, drinking water with
higher levels of TDS and hardness results in lower heart disease and
cancer modality rates.
A comment on the silica observations. In general, as researchers
continue to study specific elements in drinking water and their
relationship to cancer, we are going to see diverse and conflicting
findings.
For example, a report from Seneca County, New York revealed high levels
of selenium in the drinking water was associated with a significant
decrease in cancer. (5)
When specific elements are analyzed we find diverse and at times
confusing or conflicting results. This identical pattern was observed with
heart disease studies. But, when we look at the more inclusive water
factors such as TDS and hardness, a highly consistent, - more meaningful
picture emerges.
Burton’s work shows water with an alkaline pH is another key factor
in lower cancer mortality rates. Very few studies have examined the
positive or negative health effects of pH. However his remarks reminds one
of Schroeder’ s findings. Schroeder observed an alkaline pH resulted in
less cardiovascular disease than water with an acid pH. For many years,
people have thought that a soft water is a corrosive water that soft water
leeches substances like lead and cadmium from water pipes.
However it is the pH that causes the corrosive action of water and not
the softness, per Se. Therefore, an alkaline water should not leech heavy
metals or chemicals from galvanized or PVC pipes into our drinking water.
The positive picture emerging from this research is: drink water with
around 300 mg/L of TDS and drink a hard water with an alkaline pH to
reduce the risk of cancer mortality.
