Arsenic Results from Exposure Investigation at Coronet Industries
(a/k/a BORDEN FEED PHOSPHATE COMPLEX)
PLANT CITY, HILLSBOROUGH COUNTY, FLORIDA
Coronet Industries is located at 4082 Coronet Road, south of the city limits of Plant City, Florida.The company processes phosphates for use in animal food supplements, primarily for the poultryindustry. The facility has been operating for over 90 years. In the past, the company minedphosphate deposits in the area, but no mining operations are currently being conducted. CoronetIndustries indicated that it will end operations on March 21, 2004.
Groundwater collected from monitoring wells at the facility is contaminated with fluoride, arsenic,cadmium, lead, and alpha radiation (1). Many residents who live near the site rely on private wellsfor potable water. Public health officials and residents expressed concern that water from these wellscould contain chemical contaminants at concentrations of health concern. This contamination couldoriginate from naturally-occurring minerals in the underlying phosphate deposits, or from chemicalsreleased during operations or waste management practices at the facility.
During the first two weeks of August 2003, State officials collected water samples from the privatewells of residents who lived within a ¼-mile radius of the facility. The Department of HealthLaboratories tested water samples from 43 homes for volatile organic chemicals, metals (includinglead, cadmium, arsenic, and boron), fluoride, and gross alpha radiation. The results of these testindicated that water from some of the wells contained boron, arsenic, and alpha radiation atconcentrations in excess of state drinking water standards.
In order to better characterize human exposure to site-related chemicals for residents who wereconsuming the water, The Florida Department of Health (FDOH), the Hillsborough County HealthDepartment (HCHD), and the Agency for Toxic Substances and Disease Registry (ATSDR)conducted an Exposure Investigation (EI). We collected urine samples from residents whose wellshad been sampled by the state and tested the urine samples for lead, cadmium, uranium, arsenic,fluoride, and boron.
On December 5, 2003, ATSDR and FDOH released a health consultation that discussed the resultsof the urine testing for lead, cadmium, uranium, fluoride, and boron (2). At the time we released thisreport, the urine samples had not yet been tested for speciated arsenic. These tests have since beencompleted, and this report will discuss the arsenic test data.
This report is being issued as a follow up to the Health Consultation of December 5, 2003. Thisearlier consultation should be consulted for details on the selection of target population, sample collection and handling, and laboratory analysis of the urine samples for lead, cadmium, uranium,fluoride, and boron. This report will only discuss the arsenic testing.
During the week of August 12, FDOH sent a flier to potential participants that alerted them to theupcoming EI. The flier informed them that urine samples would be collected the following weekfrom eligible residents. The residents were advised not to eat any fish or shellfish for four days priorto donating a urine sample. These instructions were given because after eating fish, the urinaryarsenic level could be temporarily elevated because of the high content of organic arseniccompounds in fish and shellfish. Nevertheless, people who had recently eaten fish were notexcluded from the investigation, since biomarkers of exposure for the other contaminants would notbe affected.
The National Center for Environmental Health Laboratory (NCEH) in Atlanta analyzed 104 urinesamples for total arsenic using inductively coupled plasma dynamic reaction cell mass spectroscopy. The analytical limit of detection for total arsenic was 0.6 micrograms per liter (µg/L). It was notpossible to analyze the urine samples provided by two people for arsenic because of the smallvolume of urine that was provided.
NCEH analyzed 106 urine samples for speciated arsenic using high performance liquidchromatography inductively coupled plasma dynamic reaction cell mass spectroscopy. Theanalytical limit of detection for the arsenic species ranged from 0.4 to 1.7 µg/L. Creatinineconcentrations were measured using an automated spectrophotometric technique.
After a person ingests arsenic in water or food, the arsenic is rapidly excreted from the body into theurine. Researchers have estimated that 45-85 percent of arsenic is excreted into the urine within 1-3days after ingestion (3). Therefore, urine concentrations of arsenic are an indicator of recentexposure.
The urine samples were first analyzed for the total concentration of all forms of arsenic, whichincludes both inorganic and organic arsenic. Low concentrations of naturally-occurring, inorganicarsenic are present in water and some foods. Relatively high concentrations of naturally-occurringarsenic are present in fish and shellfish. However, most of the arsenic in fish and shellfish is in anorganic form, especially as arsenobetaine and arsenocholine. These organic forms of arsenic are oflittle health concern, because they are relatively non-toxic as compared to inorganic arsenic. In fishand shellfish, from 2 to 10 percent of the total arsenic can be in the form of inorganic arsenic or itsmethylated metabolites (4). Trace concentrations of organic arsenic can also be found in chickenmeat, because fish meal is sometimes added to chicken feed.
To differentiate between inorganic and organic forms of arsenic in the urine samples, a secondanalysis was conducted for "speciated" arsenic, which consists of inorganic arsenic (As+3 and As+5)and its methylated metabolites (monomethylarsonic acid and dimethylarsonic acid). The results ofthis test are of greater health significance because of the toxicity of inorganic arsenic. The results ofthis analysis could also be indicative of exposure to inorganic arsenic in drinking water. However,well water testing by the Department of Health Laboratories showed that water from only one wellcontained arsenic at a concentration in excess of the pending state drinking water standard of 10 µg/L. The arsenic concentration (13 µg/L) in water from this one well only slightly exceeded thestate standard.
Table 1 presents a statistical summary of the concentrations of total arsenic detected in the urinesamples. The arsenic concentrations are also reported as creatinine-normalized values to correct forurinary dilution.
|range||0.7 - 604||1.7 - 557|
After the ingestion of a seafood meal, urinary arsenic concentrations can increase to a concentrationof 1,000 µg/L or more. However, in people with no unusual exposure to arsenic or recent ingestionof seafood, total urinary arsenic concentrations are usually less than 50 µg/L (5, 6). In thisinvestigation, 10 of the participants had total urine arsenic levels of 50 µg/L or more. Todifferentiate inorganic from organic arsenic, all urine samples were tested for speciated arsenic.
In reporting the results of the speciated arsenic analyses, the concentrations of inorganic arsenic andits methylated metabolites were added together to yield total inorganic arsenic. As shown in Table2, the concentrations of total inorganic arsenic in 106 urine samples ranged from not detected to 30.8µg/L. There is no national reference range for background concentrations of speciated arsenic inurine samples from the general United States population. However, the results of several studies inthe scientific literature indicate that the concentrations of speciated inorganic arsenic in people withno unusual exposure to arsenic are usually less than 20 µg/L (7, 8, 9).
|range||ND - 30.8||ND-23.9|
ND - not detected
The average urinary concentration of speciated inorganic arsenic in the participants of thisinvestigation was 6.1 µg/L. Only one participant had a speciated inorganic arsenic concentration(30.8 µg/L) in excess of 20 µg/L. However, this person also had a very high concentration ofarsenobetaine (490 µg/L) in his urine sample, which indicates he likely ate seafood shortly beforedonating a urine sample. Therefore, the elevated speciated inorganic arsenic concentration in thisperson is likely due to the inorganic arsenic content of the seafood he ate.
Several studies have examined the health effects of long-term exposure to arsenic in the workplace. These studies reported that chronic exposure to high doses of arsenic, primarily in workplace air, isassociated with peripheral neuropathy, altered kidney or liver function, and lung cancer. However,when adverse health outcomes were observed, the exposures, as measured by urine arsenic levels,were higher than those measured in this study. To protect adult workers in occupational settings,the American Council of Governmental and Industrial Hygienists has recommended a BiologicalExposure Index for arsenic of 35 µg/L (10). None of the inorganic arsenic levels in urine detectedin this investigation exceeded this level. Therefore, the urine arsenic levels measured in theparticipants of this investigation were below levels that have been associated with adverse healthoutcomes.
The participants in this investigation varied considerably in their use of well water. Some reportedusing well water for drinking, cooking, and non-potable purposes in their household. Others usedwell water only for non-potable purposes and used bottled water for drinking. Some of theparticipants reported using water treatment devices such as water softeners, particulate filters, carbonfilters, and reverse osmosis units. Furthermore, several of the participants reported that they stoppeddrinking the water after they received their water test results from the State, which was a day or twobefore this investigation was conducted. In addition, whenever possible, the State collected watersamples prior to its passage through treatment devices. Therefore, the concentrations of chemicalsin the raw water could differ from what the participants were drinking from the tap.
Because of these multiple sources of variability, it is difficult to estimate exposures to drinking watercontaminants. Furthermore, this investigation was offered as a public health service, so we did notexclude any residents whose wells had been tested, regardless of their water consumption historyor use of water treatment devices. Arsenic is rapidly excreted from the body after ingestion, so theurine levels are strongly influenced by recent consumption. Some of the participants in thisinvestigation had stopped drinking the water a day or two before they donated a urine sample. Theurine levels of arsenic that were measured in residents who were not drinking the water at the timeof the investigation may not be representative of their past exposures.
In March 2004, ATSDR mailed individual test results and an explanation of their significance to theparticipants of this investigation. A toll-free telephone number was provided so the participants ortheir physicians could call ATSDR if they had questions about their test results. The FDOH will mailcopies of this report to the participants.
The urine arsenic test results indicated that the participants in this investigation were not beingexposed to elevated doses of inorganic arsenic from the environment. The urine arsenicconcentrations detected in this investigation have not been associated with adverse health outcomes. ATSDR concludes that the urine arsenic concentrations measured in this investigation pose noapparent public health hazard.
Residents whose wells produce water that contains contaminants in excess of drinking waterstandards should continue to use bottled water or an alternative water source for potable purposes.
The Florida Department of Health will prepare several health consultations for the Coronet Industriessite. These reports will assess all available data and information for the site and determine ifenvironmental contamination from the site poses a public health hazard.
Kenneth Orloff, PhD, DABT
Agency for Toxic Substances and Disease Registry
Michael L. Patterson, MD
Agency for Toxic Substances and Disease Registry
Susan A. Bland
Florida Department of Health
Bureau of Environmental Community Health
- Florida Department of Health; Brief Petition Scoping Report: Coronet Industries; Plant City, Florida; June 18, 2003.
- Agency for Toxic Substances and Disease Registry; Health Consultation: Exposure Investigation at Coronet Industries; December 5, 2003.
- Agency for Toxic Substances and Disease Registry, Toxicological Profile for Arsenic (Update); September 2000.
- M Vahter; Environmental and Occupational Exposure to Inorganic Arsenic; Acta Pharmacol Toxicol 59(Suppl VII) 31-34 (1986).
- National Research Council; Arsenic in Drinking Water; National Academy Press; Washington, D.C. 1999.
- S Binder et al.; Arsenic exposure in children living near a former copper smelter; Bull Environ Contam Toxicol 39 114-121 (1987).
- LR Johnson and JG Farmer; Urinary arsenic concentrations and speciation in Cornwal residents; Environ Geochem Health 11 39-44 (1989).
- GE Jensen et al.; Occupational and environmental exposure to arsenic - increased urinary arsenic level in children; Science Total Environ 107 169-177 (1991).
- P Andren et al.; Environmental exposure to lead and arsenic among children living near a glass works; Science Total Environment; 77 25-34 (1988).
- American Conference of Governmental Industrial Hygienists; Documentation of the Biological Exposure Indices; Cincinnati, Ohio, 2001.