Nitrate
and Your Health
For
years, nitrates have been effective in lawn and garden
fertilizers by providing grass and shrubs with life-giving
nutrients. However, the accumulation of these fertilizers
can eventually leach through the soil to invade wells.
While
this is not surprising with shallow wells, deep wells are
frequently affected, particularly if they were dug subsequent
to a first well. An Iowa State University Special Report(1)
found that old or depleted wells, often just abandoned
and not filled with concrete as most water specialists
recommend, become readily available reservoirs for runoff
and excessive groundwater. As they refill with surface
water, they may become concentrated with potentially toxic
lawn care and agricultural chemicals, contaminating the
new well.
In
January 1992, the U.S. Environmental Protection Agency
(EPA) released the results of a sophisticated national
survey(2) of nitrates and pesticides in drinking water
wells. The National Pesticide Survey (NPS) tested water
from 1,349 community and domestic rural wells. Samples
were taken in every state. Nitrate detection was projected
in 57 percent of the rural domestic wells (RDWs), and 52.1
percent of the community water system (CWS) wells in the
United States. Approximately 22,500 infants younger than
one year old consuming water from RDWs were projected to
be exposed to nitrate-nitrogen exceeding the 10 milligram
per litre safe drinking water limit. The CWS population
is projected to be 43,500 infants.
Nitrates
which are ingested by infants or young farm animals changed
into dangerous nitrites, which can seriously affect the
blood's ability to release oxygen. Once these nitrites
enter the circulatory system, they combine with the blood's
haemoglobin and prevent life-sustaining oxygen from being
carried to body tissues.
Nitrates
and Haemoglobin
Haemoglobin is the part of the red blood cell which distributes oxygen to the
body's cells. Under normal conditions, the haemoglobin is an efficient transporting
mechanism, easily releasing oxygen to the cells. However, infants less than
three months of age have nitrate reducing bacteria in their digestive systems.
These bacteria convert nitrates to nitrites, which bind strongly with blood
haemoglobin and prevent sufficient oxygen transport in the baby. Shortness
of breath, susceptibility to illness, heart attack, or even death by asphyxiation
can result. By age six months, hydrochloric acid concentrations in the stomach
rise, killing the nitrate reducing bacteria. Nitrates are therefore not a concern
in older children and adults.
When
In Doubt, Test It Out!
The presence of nitrates and nitrites can be confirmed through testing by the
County Health Department or by a state- or EPA-certified laboratory. Once detected,
point-of-use (POU) water treatment equipment is generally required to lower
these levels acceptably.
For acceptable levels of nitrite in drinking and cooking water, the reverse
osmosis and distillation processes are widely used.
Those
users on the more than 15 million private wells in the
USA are solely responsible for their water's safety,
and widely use POU treatment to solve problems. Where there
is a municipal system, some communities have tried to control
high nitrate levels in their central water system by using
a "split stream" arrangement. In this system,
a portion of the water is drawn off and treated using an
anionic nitrate removal process. The treated water is then
blended with the untreated water to dilute the nitrate
concentrations. While this method is effective in lowering
nitrate levels, a point-of-use system should still be preferred
by consumers who want to control harmful nitrate levels
in their home water system.
If
you suspect a problem, have your water tested at once.
It's a simple step towards protecting your family's health.
References:
1. "The Nitrate Problem. Special Report No. 34." Iowa State University
of Science and Technology, Cooperative Extension Service in Agriculture and
Home Economics; Ames, Iowa, August 1963.
2. "National Pesticide Survey - Phase II" Office of Pesticides and
Toxic Substances, USEPA, Washington , D.C., 1992.
End
of Article
[
More Articles ]
Remember...
Freshly Squeezed
Water offers superb Reverse Osmosis Filtration
Systems with a number of different financial options
to make our system affordable for all. You can
find more information
on our Reverse Osmosis Water systems throughout
this site.
|
|