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TOXIC METALS IN DRINKING WATER TR-2-82-17- May 1982 TOXIC METALS IN DRINKING WATER by Anthony V. Colucci, Sc.D. COLUCCI AND ASSOCIATES, INC. 15305 Calle Enrique. Suite D Morgan Hill, CA95037 Richard J. Thompson, Ph.D. Preface Historically, there has been a keen awareness that certain metals play a central role in human disease processes. However, recently the issue of metal-induced adverse health effects has moved into an area of both greater prominence and urgency. Many of these toxic metals reach humans via the water they drink and arise from leaching of the pipes through which it is transported. Thus, it was felt a review of this topic would be both timely and needed. We believe this review will serve to focus needed attention on the issue of how toxic metals reach humans via the water they drink and thereafter induce or participate in the induction of a variety of diseases. We are grateful for the review and
comments of this paper by Dr. S.D. Lee of the U.S. Environmental
Protection Agency and by Dr. A. Furst of the It has long been recognized that metals
play a central role in the cause or aggravation of a variety of
diseases. This situation has posed some per- It is now known that human intake of metals occurs from exposure to a variety of sources: food, air, soil and drugs. Another very important and readily available source is drinking water. This fact has been recognized by the EPA who has promulgated drinking water standards for several metals known to be harm-ful (Table #1 ). Drinking water and the source of the metals it contains are the subject of this report. Metals enter drinking water from a variety of sources, some natural and some man-made. Natural sources include simple dissolving of minerals from the earth through which the water percolates or over which it flows. Some metals arise from fallout of windblown dust. Man-made sources include industrial waste discharge into water along with emissions from automobiles or power plants. Another very important means by which metals enter water is by leaching from the surface and joints of pipes used for potable water distribution. It is well documented that metals leach into water from a variety of metal pipes (lead, copper or galvanized). For the purpose of this discussion we
will focus on several toxic metal which are found in drinking water
which leach from the pipes through which the water is transported. We
will examine factors that contribu- The potential problem is by no means
small, since most dwelling units in the United States are supplied with
water through metal pipes. These materials have long been and remain the
standard of the plumbing Lead The first example of a harmful metal which reaches man via drinking water is lead. It is estimated that 10-15% of daily human lead intake is via drinking water. Therefore the U.S. EPA under the Safe Drinking Water Act, has established a Maximum Contaminant Level for lead of 0.005 mg/liter or 50ppb (parts per billion) (see Table #1.) This is a worthwhile effort and merits
continued concern. However, based on a large number of surveys it has
been established that a high percentage of the water-borne lead we drink
comes from the Evidence suggests this problem of lead
solubility is linked to both the pH (acidity or alkalinity) of the water
as well as the level of other minerals it contains (see for example the
Seattle EPA Study). Acidic water, which is low in minerals, causes more
lead to leach out of pipe and joints. This is not surprising inasmuch as
it has been long known that waters that are so What, then, can be said of the
consequences of this dissolved lead and human disease? In a phrase, too
much and none of it good. The list of the diseases and symptoms which
have been associated with ingestion Suffice it to state that the lead
adversely affects almost every aspect of human physiology. It is neurotoxic.
I.e., it causes both pathologic Lead is hemotoxic
causing a shortened life span of red blood cells, alteration of
hemoglobin, and interference with normal blood oxygen transport. Recent data from animal studies suggests
that lead contributes to or causes excess renal tumors establishing that
it has carcinogenic or mutagenic Clearly,lead ism a "bad actor" and its presence in potable water can be traced in part to the combination of metal plumbing systems (copper or lead) and common water characteristics. Cadmium Conditions which favor lead leaching from pipes and joints also favor leaching of cadmium and copper. For cadmium, the EPA (Table #1) has recommended a drinking water standard of 0.01 mg/liter (10ppb). In man, drinking water is the source of 10% of daily cadmium intake and once again metal plumbing is implicated. As we shall discuss, cadmium leaching is commonly associated with both galvanized and copper pipe. Cadmium is a common impurity in the zinc used to galvanize steel pipe. Like lead, cadmium adversely affects a broad spectrum of human physiological processes. Symptoms of cadmium intoxication range from acute poisoning to more long-term damage to the liver and kidneys. Attention to the role of cadmium in human disease traces its origins to Japan wherein a peculiar disease known as Itai-itai was first described over a decade ago by Tsuchiya. This disease has one outstanding characteristic: proteinuria (protein in the urine). This symptom is known to be secondary to destraction of kidney tubules essential to their proper function. Also, cadmium has been linked to hypertension and increased cardiovascular disease. To make matters worse, it can now be shown that the adverse health effects from cadmium are additive with those from lead. This further compounds the problem since the same water quality factors promote leaching of both metals from metallic plumbing systems. Most disturbing is the recent finding that cadmium also produces adverse effects on the reproductive system. This metal has been shown to be spermatotoxic (kills sperm) and fetotoxic (toxic to the growing fetus). As a result, cadmium intoxication has now been directly linked to increased mortality of the newborn. Limited data also suggests a role for cadmium in carcinogenesis, however this role is not yet firmly established or clearly defined. Thus, even acting alone, cadmium can be considered to be a very serious environmental toxin. This fact coupled to the finding that its actions are often additive to an equally serious toxic such as lead should serve to further heighten public health concern. Because the presence of both lead and cadmium in drinking water is increased by corrosive water, the public health problems they pose are significant on both a national and global scale. In the U.S., aggressive water is most commonly found on the East Coast and in the vast area west of the Sierras. Fortunately, less aggressive water is generally found in the Intermountain areas where rainfall is sparse and wells are deep. However, a quick review of the population distribution in the U.S. reveals that high population density and corrosive water are, more often than not, synonymous. Copper In contrast to cadmium and lead, copper presents a more complex picture. Copper is essential for life and for years the primary focus of concern has been on alleviation of a deficiency state rather than on its toxicity per se. Recently, however, this emphasis has begun to shift. Currently the U.S. EPA Drinking Water Standard for Copper is 1mg/liter or l000ppb. However, this is based on the levels required to avoid a bad taste or smell (organoleptic) rather than on a recognized health effect. Despite this current status, increasing evidence is accumulating which implicates excess copper in the cause or aggravation of disease. Regarding toxicity, for example, early reports have now been confirmed which link copper to hemolysis (red cell damage) and mental disturbances (schizophrenia) Interestingly, copper related diseases seem to have a predilection for the young (infants), chronically III or genetically predisposed humans. There have been reports of infant illness (poisoning, Prostration, edema, lung damage) and death which have occurred as a result of copper accumulation in drinking water. In one case the level implicated was 0.8 mg/liter or 800ppb, which is less than the current Drinking Water Standard. In addition, kidney disease patients on dialysis, who have been inadvertently intoxicated by copper laden water, have experienced red cell damage and varying degrees of mental disorientation including psychosis. In other subjects, nausea, diarrhea and jaundice have been observed secondary to copper intoxication. In a pattern of consistency, excess copper has been linked to hemolysis (red cell rupture) in a group of patients suffering from a disease which is characterized by a genetic deficiency of a red cell enzyme called Glucose-6-phosphate dehydrogenase. This enzyme is essential to proper energy metabolism and cell life and its deficiency predisposes the cell to early death and damage. Thus, copper intoxication, like lead and cadmium intoxication clearly can lead to illness and death. Finally, and most important for our purposes, evidence suggests that the increased use of copper pipe in the last 20 years is implicated in the growing problem of zinc deficiency which we are now observing. It has been suggested that the excess copper we receive from the attack of aggressive water on copper pipes retards the uptake of zinc from the food we eat. This retardation causes a metabolic imbalance that serious affects a variety of cellular and organ processes. The particular effects of zinc deficiency are dwarfism, circulatory abnormalities, and a loss of the sense of taste. Recently, a survey of copper and cadmium in water has been made from a variety of sources and transported through several types of pipe. These data which are derived from a report by H.A. Schroeder, are summarized in Table 3. As can be seen, transporting water through copper or galvanized pipe can cause a significant rise in the level of either cadmium or copper or both. The potential health effects of such leaching.as noted above, can be extremely serious. Other Metals The story by no means ends with lead, cadmium and copper, for indeed other materials play a rote in disease. Certain chemical forms of nickel play a role in carcinogenesis, while chromium is both toxic and a suspect carcinogen. Even iron, which like copper is essential, has been shown, in excess to interact with copper to contribute to psychotic disturbances such as schizophrenia. Recently, excess iron has also been linked to a greater incidence of heart disease in both men and post menopausal women. Given these facts it is not surprising
that public concern over these long ignored hazards of metals has
recently heightened. Indeed, public health
bodies, such as the American Medical Association and the U.S. EPA, have
recently expressed concern over the leaching of toxic metals into
potable water from various metal pipes. This is due to the fact that the
scientific findings, however frightening, must be balanced against one
immutable reality: humans must drink water to survive. Yet another
reality is that only a select few individuals can obtain this water from
crystal clear springs high in a pristine forest. Most humans must, at
some point, turn on the tap to obtain water for drinking, as well as for
cooking and bathing. Summary It is our belief that the problem need not be tolerated and, in fact, that the solution has been at hand for several years. The facts we have marshalled in this brief paper from a host of sources, lead clearly to the following conclusions:
NATIONAL PRIMAUT DRINKING WATER
REGULATIONS (Metal Contaminants)
*1 mg/l (milligram per liter) is the equivalent concentration of one part per million, or about one teaspoon in 1300 gallons of water TABLE 2 DISTRIBUTION OF LEAD IN EARLY MORNING
WATER SAMPLES TAKEN
* All home water distribution systems
consisted of copper tubing with lead solder. TABLE 3*
*Data abstracted from H.A. Schroeder, Traace Elements in Man, 1969. (9) EPA Drinking Water Standards:
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