ENVIRONMENTAL
20, 318-324 (1979)
RESEARCH
Cardiovascular Disease Death Rates in Communities with Elevated Levels of Barium in Drinking Water G.R.
BRENNIMAN,
T. NAMEKATA,
W.H.
KOJOLA, B.W.
CARNOW,
AND P. s. LEVY University
of Illinois
at the Medical Center, School of Public Chicago. Nlinois 60680
Health,
P.O.
Box
6998,
Received March 20, 1979 A retrospective epidemiological analysis of age- and sex-adjusted cardiovascular death rates for the years 1971- 1975 was conducted to examine differences between Illinois communities with elevated drinking water barium levels (~2.0- 10.0 mg/liter) and communities with little or no barium (0.0-0.2 mg/liter). This study was conducted to examine human health effects associated with ingestion of barium in drinking water exceeding the maximum contaminant level for barium of 1 mgliter as stipulated in the National Interim Primary Drinking Water Regulations. Results of this mortality study revealed that the high barium communities had significantly higher (P < 0.05) death rates for “all cardiovascular diseases” and “heart disease” compared to the low barium communities. Since there was a greater population change in some of the high barium communities compared to the low barium communities and no method of controlling for removal of barium by home water softeners, any inferences drawn about this finding must be interpreted with caution. Further study is needed to determine what the maximum allowable levels should be for barium in drinking water.
INTRODUCTION
An advisory report of the Illinois Institute for Environmental Quality (Advisory Report on Health Effects of Barium in Water, 1974) has identified 16 cities and two subdivisions in Illinois, totaling more than 150,000 individuals, with drinking water sources exceeding the maximum contaminant level (MCL) of 1 mg/liter for barium as stipulated in the National Interim Primary Drinking Water Regulations (U.S. Environmental Protection Agency, 1977). The barium concentrations in these communities ranged from 1.1 to 10.0 mg/liter (Table 1). All of the water supplies with barium exceeding 1 mg/liter are from deep rock or drift wells in northern Illinois and are the result of a naturally occurring geochemical pollutant (Gilkeson et al., 1978). Acute human and animal exposures demonstrate the most characteristic action following barium ingestion to be an intense stimulation of smooth, striated, and cardiac muscle (Diengott et al., 1964; Goodman and Gilman, 1970; Roza and Berman, 1971). Symptoms produced in accidental human ingestion include salivation, vomiting, ventricular tachycardia, hypertension, flaccid paralysis of skeletal muscle, and, if poisoning is severe, respiratory muscle paralysis and ventricular fibrillation which can lead to death. Animal studies indicate that injected barium has a profound effect on the cardiovascular system, leading to arterial hypertension, extrasystoles, multiple premature ventricular contractions, or ventricular fibrillation (Smith et al., 1940; Roza and Berman, 1971). Barium chloride perfusion will initiate pacemaker activity in cat and rat ventricular muscle 318 0013-9351/79/0603 1%07$02.00/0 Copyright All rights
Q 1979 by Academic Press. Inc. of reproduction in any form reserved.
DEATH
RATES AND BARIUM TABLE
ELEVATED
BARIUM
LEVELS
County
City or village
Bureau Carroll Cook De Kalb DeKalb DeKalb Dewitt DuPage Kane Kane Kane Kane Kendel Knox Lake McHenry McHenry Rock Island Stephenson Winnebago
Seaton Shannon Hoffman Estates Briarwood Subdivision DeKaIb Malta Farmer City Hanover Park Burlington Elgin West Dundee Elgin State Hospital Hollis Park Subdivision Oneida Lake Zurich Algonquin Crystal Lake Croppers German Valley Rock Cut State Park
319
IN WATER
1
IN ILLINOIS
DRINKING
Total population (19701 251 848 22,238 NA’ 32,949 961 2.211 11,916 456 55.69 1 3,295 NA NA 728 4,082 3.515 14,541 NA 206 NA
WATER”
Raw water concentration (mgiliterl” 1.8 2.9-4.7 1.6-5.1 1.1 1.1-1.9 1.5-2.3 1.2 1.4-7.0 1.8-2.3 1.7-6.8 2.9- 10.0 2.8 1.1 1.25 1.3-2.1 4.0-8.3 2.2- 10.0 1.4 4.4-5.6 2.0
153.894 ” Advisory Report on Health Effects of Barium in Water. 1974. ” Sources of drinking water is predominantly from rock wells. Values represented from at least one well supply. ’ NA. data not available.
fibers followed by spontaneous beating (Slavicek, 1972; Mascher, 1973). The barium ion can also cause the release of catecholamines (epinephrine and norepinephrine) from the adrenal medulla and norepinephrine release from adrenergic synapses (Douglas, 1968; Rubin, 1970; Douglas, 1976). Recent evidence indicates that individuals with essential hypertension have significantly higher plasma catecholamine levels than normotensives (Engelman et al., 1970: Louis et al., 1973: DeChamplin er al., 1976). Furthermore, epidemiological studies have shown that barium levels well below 1 mg/liter in drinking water are associated with decreases in cardiovascular disease mortality (Elwood et al., 1974; Schroeder and Kramer, 1974). However, barium levels reported in these studies are as much as several hundredfold less than those found in the high barium communities in Illinois. This study has examined retrospectively whether human cardiovascular disease death rates are significantly higher (P < 0.05) in Illinois populations ingesting 2.0 mgliter barium or greater from their drinking water, as compared to Illinois populations that ingest 0.2 mg/liter or less. The present drinking water standard for barium has been extrapolated from an occupational air standard of 0.5 mg/m”, and has no known degree of safety (Kojola et al., 1979). This mortality study is the
320
BRENNIMAN
ET
AL.
first of its kind to assess the chronic human health effects associated with ingestion of elevated barium in drinking water. It was conducted to more accurately define a safe level of barium in drinking water. MATERIALS AND METHODS Death rates for cardiovascular diseases, classified by the “International Classification of Diseases, Adopted” (ICDA) (U.S. Department of Health, Education and Welfare, 1968) were retrospectively determined from Illinois State Death Data for the years 1971-1975. Comparisons of these age-adjusted death rates were made between communities with high barium levels (32.0-10 mg/liter) and communities with low or no barium (0.0-0.2 mg/liter) in their public water supplies. The major difference in the chemical composition of the public water supplies studied was in the barium concentration. When data for the chemical composition of the high and low barium communities were obtained from the Illinois Environmental Protection Agency for the years 1971- 1975, it was found that these drinking water supplies contained no (below the detection limits of atomic absorption) cadmium, chromium, copper, lead, mercury, nickel, silver, or cyanide. All of the supplies had hard water. The mean calcium and magnesium concentrations in the high barium communities were, respectively, 51.8 and 20.8 mg/liter, while the low barium communities had mean concentrations of calcium and magnesium of 65.0 and 35.3 mg/liter, respectively. The mean sodium concentration in the high barium communities was 37.2 mgliter, while the low barium communities had a mean ,sodium concentration of 23.7 mg/liter. Trace amounts of iron (~1 mg/liter), manganese (co.02 mg/liter), boron (< 1 mg/liter), and zinc (
20, 318-324 (1979)
RESEARCH
Cardiovascular Disease Death Rates in Communities with Elevated Levels of Barium in Drinking Water G.R.
BRENNIMAN,
T. NAMEKATA,
W.H.
KOJOLA, B.W.
CARNOW,
AND P. s. LEVY University
of Illinois
at the Medical Center, School of Public Chicago. Nlinois 60680
Health,
P.O.
Box
6998,
Received March 20, 1979 A retrospective epidemiological analysis of age- and sex-adjusted cardiovascular death rates for the years 1971- 1975 was conducted to examine differences between Illinois communities with elevated drinking water barium levels (~2.0- 10.0 mg/liter) and communities with little or no barium (0.0-0.2 mg/liter). This study was conducted to examine human health effects associated with ingestion of barium in drinking water exceeding the maximum contaminant level for barium of 1 mgliter as stipulated in the National Interim Primary Drinking Water Regulations. Results of this mortality study revealed that the high barium communities had significantly higher (P < 0.05) death rates for “all cardiovascular diseases” and “heart disease” compared to the low barium communities. Since there was a greater population change in some of the high barium communities compared to the low barium communities and no method of controlling for removal of barium by home water softeners, any inferences drawn about this finding must be interpreted with caution. Further study is needed to determine what the maximum allowable levels should be for barium in drinking water.
INTRODUCTION
An advisory report of the Illinois Institute for Environmental Quality (Advisory Report on Health Effects of Barium in Water, 1974) has identified 16 cities and two subdivisions in Illinois, totaling more than 150,000 individuals, with drinking water sources exceeding the maximum contaminant level (MCL) of 1 mg/liter for barium as stipulated in the National Interim Primary Drinking Water Regulations (U.S. Environmental Protection Agency, 1977). The barium concentrations in these communities ranged from 1.1 to 10.0 mg/liter (Table 1). All of the water supplies with barium exceeding 1 mg/liter are from deep rock or drift wells in northern Illinois and are the result of a naturally occurring geochemical pollutant (Gilkeson et al., 1978). Acute human and animal exposures demonstrate the most characteristic action following barium ingestion to be an intense stimulation of smooth, striated, and cardiac muscle (Diengott et al., 1964; Goodman and Gilman, 1970; Roza and Berman, 1971). Symptoms produced in accidental human ingestion include salivation, vomiting, ventricular tachycardia, hypertension, flaccid paralysis of skeletal muscle, and, if poisoning is severe, respiratory muscle paralysis and ventricular fibrillation which can lead to death. Animal studies indicate that injected barium has a profound effect on the cardiovascular system, leading to arterial hypertension, extrasystoles, multiple premature ventricular contractions, or ventricular fibrillation (Smith et al., 1940; Roza and Berman, 1971). Barium chloride perfusion will initiate pacemaker activity in cat and rat ventricular muscle 318 0013-9351/79/0603 1%07$02.00/0 Copyright All rights
Q 1979 by Academic Press. Inc. of reproduction in any form reserved.
DEATH
RATES AND BARIUM TABLE
ELEVATED
BARIUM
LEVELS
County
City or village
Bureau Carroll Cook De Kalb DeKalb DeKalb Dewitt DuPage Kane Kane Kane Kane Kendel Knox Lake McHenry McHenry Rock Island Stephenson Winnebago
Seaton Shannon Hoffman Estates Briarwood Subdivision DeKaIb Malta Farmer City Hanover Park Burlington Elgin West Dundee Elgin State Hospital Hollis Park Subdivision Oneida Lake Zurich Algonquin Crystal Lake Croppers German Valley Rock Cut State Park
319
IN WATER
1
IN ILLINOIS
DRINKING
Total population (19701 251 848 22,238 NA’ 32,949 961 2.211 11,916 456 55.69 1 3,295 NA NA 728 4,082 3.515 14,541 NA 206 NA
WATER”
Raw water concentration (mgiliterl” 1.8 2.9-4.7 1.6-5.1 1.1 1.1-1.9 1.5-2.3 1.2 1.4-7.0 1.8-2.3 1.7-6.8 2.9- 10.0 2.8 1.1 1.25 1.3-2.1 4.0-8.3 2.2- 10.0 1.4 4.4-5.6 2.0
153.894 ” Advisory Report on Health Effects of Barium in Water. 1974. ” Sources of drinking water is predominantly from rock wells. Values represented from at least one well supply. ’ NA. data not available.
fibers followed by spontaneous beating (Slavicek, 1972; Mascher, 1973). The barium ion can also cause the release of catecholamines (epinephrine and norepinephrine) from the adrenal medulla and norepinephrine release from adrenergic synapses (Douglas, 1968; Rubin, 1970; Douglas, 1976). Recent evidence indicates that individuals with essential hypertension have significantly higher plasma catecholamine levels than normotensives (Engelman et al., 1970: Louis et al., 1973: DeChamplin er al., 1976). Furthermore, epidemiological studies have shown that barium levels well below 1 mg/liter in drinking water are associated with decreases in cardiovascular disease mortality (Elwood et al., 1974; Schroeder and Kramer, 1974). However, barium levels reported in these studies are as much as several hundredfold less than those found in the high barium communities in Illinois. This study has examined retrospectively whether human cardiovascular disease death rates are significantly higher (P < 0.05) in Illinois populations ingesting 2.0 mgliter barium or greater from their drinking water, as compared to Illinois populations that ingest 0.2 mg/liter or less. The present drinking water standard for barium has been extrapolated from an occupational air standard of 0.5 mg/m”, and has no known degree of safety (Kojola et al., 1979). This mortality study is the
320
BRENNIMAN
ET
AL.
first of its kind to assess the chronic human health effects associated with ingestion of elevated barium in drinking water. It was conducted to more accurately define a safe level of barium in drinking water. MATERIALS AND METHODS Death rates for cardiovascular diseases, classified by the “International Classification of Diseases, Adopted” (ICDA) (U.S. Department of Health, Education and Welfare, 1968) were retrospectively determined from Illinois State Death Data for the years 1971-1975. Comparisons of these age-adjusted death rates were made between communities with high barium levels (32.0-10 mg/liter) and communities with low or no barium (0.0-0.2 mg/liter) in their public water supplies. The major difference in the chemical composition of the public water supplies studied was in the barium concentration. When data for the chemical composition of the high and low barium communities were obtained from the Illinois Environmental Protection Agency for the years 1971- 1975, it was found that these drinking water supplies contained no (below the detection limits of atomic absorption) cadmium, chromium, copper, lead, mercury, nickel, silver, or cyanide. All of the supplies had hard water. The mean calcium and magnesium concentrations in the high barium communities were, respectively, 51.8 and 20.8 mg/liter, while the low barium communities had mean concentrations of calcium and magnesium of 65.0 and 35.3 mg/liter, respectively. The mean sodium concentration in the high barium communities was 37.2 mgliter, while the low barium communities had a mean ,sodium concentration of 23.7 mg/liter. Trace amounts of iron (~1 mg/liter), manganese (co.02 mg/liter), boron (< 1 mg/liter), and zinc (
