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HEALTH CONSULTATION

REVIEW OF MERCURY HEALTH SERVICES' BLOOD MERCURY DATA FOR SELECTED PARISHES IN LOUISIANA
VARIOUS PARISHES, LOUISIANA


I. BACKGROUND AND STATEMENT OF ISSUES

A. Introduction

The purpose of this health consultation is to screen for elevated blood mercury levels in the areasof Louisiana for which fish consumption advisories have been issued. The 1997 Louisianalegislature provided funding to screen for the presence of mercury in blood in residents livingnear selected advisory areas. This screening is cross-sectional in design and can be used toevaluate associations between mercury levels and potential risk factors for disease development,but cannot establish a direct cause for disease development.

A large-scale Louisiana Department of Environmental Quality testing program monitors fishtissue for mercury across Louisiana. Annual fish testing has been conducted since 1994. Todate, fish in more than 100 water bodies have been evaluated. Mercury is present in the edibleportions of some fish, in all water bodies tested. Based on environmental data from fish/shellfishtissue, water, and bottom sediments which show the presence of mercury at levels which maypotentially cause adverse human health effects, fish consumption and health advisories areissued by Louisiana Department of Health and Hospitals, Louisiana Department ofEnvironmental Quality, and Louisiana Department of Wildlife and Fisheries. As of September23, 1998, sixteen mercury contaminant fish consumption advisories have been issued throughoutLouisiana (see Appendix A). Fish consumption advisories are issued based on levels ofcontaminants in specific species of fish or shellfish and provide guidance to residents on theamount of the edible portion of that fish species from a specific water body which may be eatenwithout risking adverse health effects.

The primary source of environmental exposure to mercury in the general population is throughthe consumption of contaminated fish.1 Therefore, identification of mercury in fish and theissuing of fish consumption advisories is a first step in preventing exposure. For those personswho consume more fish than recommended in the advisories, the elevated mercuryconcentrations may pose a public health hazard. The monitoring of mercury in blood furnishes ameans to assess the total exposure of individuals who eat fish from these waters.

The State of Arkansas also issues fish consumption advisories because of mercury contaminationin waterways. The greatest concentrations and most extensive occurrence of elevated mercurylevels are found in largemouth bass and flathead catfish in the lower Saline and Ouachita Rivers,Gulf Coastal Plains region of south Arkansas, that are adjacent to Louisiana. In 1992, fishtesting in Arkansas revealed mercury levels in fish exceeding FDA tolerance limits. Publicconcerns were heightened. Funds from the Governor's Emergency Fund provided baselineblood mercury screening for volunteers who lived in eight affected counties (Bradley, Calhoun,Cleveland, Dallas, Ouachita, Union, Ashley, and Drew).2,3

The Arkansas Department of Health provided blood mercury screening to 236 participants in aprevious study.2 These individuals were required to confirm that their consumption rate was aminimum of two meals per month of fish taken from impacted waters of the lower Saline and/orOuachita Rivers in order to be eligible. A meal was considered to be eight ounces of edibleportions of fish prior to cooking. Blood mercury levels in 36 participants were in the range of20-75 ppb (15%). No mercury was detected in 25% of participants tested. The limit of detectionwas 2 ppb of mercury in blood. The range of blood mercury concentrations for all participantswas 0-75 ppb.2

In Louisiana, the State Office of Public Health offered free blood mercury screening services tostate residents through the local Parish Health Units in thirteen parishes. These parishes arelocated in areas of the state where there are mercury contaminant fishing advisories. Screeningresidents for blood mercury provides data to ascertain patterns of mercury distribution amonghigh risk populations in parishes with mercury fish advisories (See Appendix B) and todetermine baseline blood mercury in residents. The state analyzed the blood samples from highrisk populations to include the blood mercury levels of pregnant women, children younger thanseven years of age, and people who eat large amounts of fish from water bodies (such ascommercial fishermen) currently under a mercury advisory.

B. Protocol

Blood samples were collected from February 28 - March 7, 1998, in Acadia, Caldwell,Evangeline, Iberia, Jefferson Davis, Lafayette, Morehouse, Ouachita, St. Landry, St. Martin, St.Tammany, Vermilion, and Washington Parishes (see Appendix C). Simultaneous with thecollection of the blood sample, the Section of Environmental Epidemiology and Toxicologywithin the Office of Public Health, conducted a written risk factor survey.

Sample Collection

Whole blood samples were collected by venipuncture. The samples were analyzed by cold vaporatomic absorption in the Office of Public Health Central Laboratory, New Orleans ChemistrySection.

Data Review

The sample results were reviewed to determine if individuals had elevated mercury levels and todescribe the relative distribution of mercury in blood among those who participated in thescreening. The International Commission of Occupational Health and the International Union ofPure and Applied Chemistry, Commission on Toxicology determined that the mean backgroundwhole blood level for total mercury in people who do not eat fish is approximately two parts perbillion. Normal total mercury blood levels in those who eat fish range from 2 to 20 ppb.1 If anindividual's blood mercury level is above 20 ppb, it is considered elevated.

It is recommended that people who are found to have those blood mercury levels decrease theirfish intake. If blood mercury levels reach 80 ppb4 in the general population or 40 ppb5 inpregnant women or children, medical evaluation by a physician is advised in addition todecreasing fish consumption (see Appendix D). Individuals with elevated blood mercury areretested after three months. Blood levels reflect recent exposure and do not indicate the totalbody burden of mercury. Appendices E - G demonstrate protocol development, times andlocations of blood mercury testing, and the participant questionnaire used in this review.

C. Special Populations of Concern

Infants, young children and pregnant or breast-feeding women are groups of concern within thegeneral population because of the impact that mercury has on developing neurological systems. Groups that depend upon fishing for a large portion of their food (subsistence) are of concernbecause of the greater amounts of potentially contaminated fish they may eat. Because lowincome people may rely on catching fish to increase their sources of protein, programparticipants were specifically recruited through the Women, Infants, and Children (WIC) federalassistance program. Commercial fishers, charter boat captains and their families also have easyaccess to large amounts of fish and may derive a larger portion of their diet from fish. In order toinform this group of the blood mercury service, a mailing was sent to all commercial fishers inthe state.

D. Quality Control

The Office of Public Health laboratory employs quality control procedures recommended by theCenters for Disease Control and Prevention for spectrophotometry of mercury in whole blood bycold vapor atomic absorption to prepare and analyze the blood mercury samples. The range ofthe percent recoveries for the material received and analyzed was between 91and 106%. Qualitycontrol procedures for sampling, chain of custody, laboratory procedures and methodology anddata analyses are conducted. The limit of detection for blood mercury level was 0.30 ppb.


II. RESULTS

Population data by parishes represented in the screening are listed in Table 1. There were 313participants in all: 187 participants were females and 126 participants were males. The yearlyincome range of the volunteers was widely dispersed. Those who earned less than $10,000 madeup 27% of all individuals screened. Eighty participants (25.6%) earned between $20,000 and$50,000 per year. Those who earned between $10,000 and $19,999 constituted 21.4% of allparticipants. There were 32 individuals (10.2%) who earned more than $50,000 yearly. Forty-eight participants (15.3%) refused to answer a question pertaining to income description.

The ethnic composition of the participants is as follows: 65.5% are white, 29.7% are black, and4.8% consider themselves some other race or ethnicity. Analysis of data by educational level ofparticipants indicated the following: 34.2% of volunteers did not graduate from high school,30.1% graduated from high school or received a General Equivalency Diploma, and 29.7%attended some college, graduated college or undertook higher educational pursuits.

Table 1.

Summary of Participants And Parishes Population Data
PARISH NUMBER OF PARTICIPANTS PARISH POPULATION *
MALE FEMALE
ACADIA 3 5 56,855
BRADLEY** (ARKANSAS) 1 0 N/A
CALDWELL 6 15 10,334
EVANGELINE 1 2 33,967
JACKSON** 0 1 15,683
JEFFERSON DAVIS 1 3 31,380
LA SALLE** 1 1 13,795
LAFAYETTE 1 5 176,592
MOREHOUSE 22 70 32,062
ORLEANS** 1 1 484,194
OUACHITA 43 48 146,449
ST. LANDRY 2 1 82,156
ST. MARTIN 1 0 45,741
ST. TAMMANY 19 16 167,242
UNION** 1 4 21,475
VERMILION 1 0 50,794
WASHINGTON 22 15 42,899
TOTAL 126 187  

* Wessex, Incorporated. 1994 Population Estimates
** These individuals presented at the clinic and were tested. Their parish/county of residence was not targeted in this screening.
N/A - not available.

Of the 313 samples individuals tested, five individuals had blood mercury levels above 20 ppb. One individual had a blood mercury level of 20 ppb. Of these six individuals (1.9%) withelevated or borderline blood mercury, there was no relationship observed in the fish speciesconsumed and the resultant blood mercury level. However, these 6 participants all ate bluecatfish, channel catfish, largemouth bass or white crappie.

The remaining 307 (98.1%) individuals exhibited blood mercury concentrations which werebelow 20 ppb. The range for all individuals with detectable blood mercury levels was 0.5 to 35.1ppb. In 48 (15.3%) of these individuals, blood mercury levels were nondetect.

Statistical Analysis

Means and medians were calculated for mercury concentrations by age, occupation, racial/ethnicgroup, education, local fish consumption, recent fish consumption, frequency of fishconsumption in the past year, pregnancy and recent fish consumption in pregnant women. Statistical analysis was performed to determine whether the means and medians were different. Because these data were not normally distributed, nonparametric statistical methods were used. A sign test (p=0.05) was performed to test for significance.6

Tables 2-10 display the blood mercury concentrations by age, occupation, racial/ethnic group,education, local fish consumption, recent fish consumption, frequency of fish consumption,pregnancy and recent fish consumption in pregnant women.

The mean blood mercury concentrations were tabulated by age group. For participants less than7 years, the mean blood mercury concentration was 2.15 ppb. For participants ages 7-19 years,the mean blood mercury concentration was 1.39 ppb. For participants ages 20-39 years, themean mercury concentration was 2.63 ppb. For participants ages 40-59 the mean mercuryconcentration was 4.45 ppb. For participants, ages 60 years and older, the mean mercuryconcentrations was 4.30 ppb (Table 2). Mean mercury concentrations were significantly lowerin the <7 age group as compared to all age groups as a whole. Mean and median mercuryconcentrations were significantly lower in the 7-19 age group as compared to screeningparticipants as a whole.

Table 2.

Mercury Concentration (ppb) by Age
Age <7
(n=22)
7 - 19
(n=32)
20-39
(n=89)
40-59
(n=75)
60+
(n=93)
Mean *2.151.392.634.454.30
Median*1.750.752.12.83.0
Range of ConcentrationsND - 8.70ND - 8.70ND - 30.7ND - 35.1ND - 22.9

* Calculations of mean mercury concentration and median include method detection limit (0.15) for samples which are non-detect.
ND- not detected

Occupation was an indicator of higher blood mercury concentrations in this sample as shown inTable 3: the mean blood mercury concentration for commercial fishers and their householdmembers is 6.65 ppb as compared to 3.21 ppb in all others tested. Mean and median mercuryconcentrations were significantly higher in commercial fishermen and their household membersthan those in other occupations.

Table 3.

Mercury Concentration (ppb) by Occupation
OccupationCommercial Fishers andHousehold Members (n=18 )Other (n=295)
Mean*6.65 3.21
Median*4.952.20
Range ofConcentrationsND - 35.1ND - 30.7

* Calculations of mean mercury concentration and median include method detection limit (0.15) for samples which are non-detect.
ND- not detected.

Analysis of the data by race in Table 4 indicates that the mean level in African-Americans (2.43ppb) is approximately 40% lower than in whites (3.84 ppb) and others (3.67 ppb) in this sample. This lower mean blood mercury level in blacks is statistically significant when compared to thelevel in whites. Also, other racial/ethnic groups had significantly lower blood mercuryconcentrations as compared to whites.

Table 4.

Mercury Concentration (ppb) by Race/Ethnic Group
Race/EthnicityWhite (n=205 )Black (n= 93)Other (n=15)
Mean*3.842.43 3.67
Median*2.301.702.20
Range ofConcentrationsND - 35.10ND - 30.7ND - 20.60

* Calculations of mean mercury concentration and median include method detection limit (0.15) for samples which are non-detect.
ND- not detected

Table 5 demonstrates that as educational levels of participants increased, mean blood mercuryconcentrations decreased. In individuals who did not graduate high school, the average bloodmercury level was 3.67 ppb; high school graduates and GED holders had average blood mercurylevels of 3.43 ppb; college graduates and those with higher education had average blood mercurylevels of 2.96 ppb. None of the mean or median blood levels by educational status weresignificantly different.

Table 5.

Mercury Concentration (ppb) by Education
Education < High School
(n=107 )
High School/GED
(n=93 )
Some College +
(n=97)
Mean* 3.673.43 2.96
Median*2.202.202.20
Range ofConcentrationsND - 35.10ND - 26.70ND - 18.10

* Calculations of mean mercury concentration and median include method detection limit (0.15) for samples which are non-detect.
ND- not detected

Table 6 presents blood mercury results from participants who indicated they ate fish caughtwithin 40 miles of their homes. These data show that this population had more than double themean concentration of blood mercury (4.34 ppb) than those who did not eat local fish (1.76 ppb). Mean blood mercury concentrations were significantly lower in participants who did not eatlocal fish as compared to those who ate fish caught within 40 miles of their homes.

Table 6.

Mercury Concentration (ppb) by Local Fish Consumption
Local Fish Consumption Eat fish caught within 40 miles of home (n=186) Do not eat local fish or don't know (n=108)
Mean* 4.34 1.76
Median* 2.80 1.50
Range of Concentrations ND - 35.1 ND - 7.60

* Calculation of mean mercury concentration and median include method detection limit (0.15) for samples which are non-detect.
ND- not detected

Table 7 indicates that those who had eaten fish in the previous three days prior to the time thatthe blood sample was taken had greater blood levels (4.55 ppb) than those who had not eaten fishin the previous three days (2.59 ppb). However, this increase was not statistically significant.

Table 7.

Mercury Concentration (ppb) by Recent Fish Consumption
Recent FishConsumption Ate fish in last three days
( n =120)
Did not eat fish in past three days or don't know
(n=175)
Mean*4.55 2.59
Median*3.001.90
Range ofConcentrationsND - 35.10ND - 20.6

* Calculations of mean mercury concentration and median include method detection limit (0.15) for samples which are non-detect.
ND- not detected

There was also a trend among those who reported a greater frequency of fish consumption duringthe last year. The highest mean concentration of blood mercury (5.10 ppb) was found inparticipants who reported eating fish more than once per week. The next highest level (3.56ppb) was found in those who ate fish once per week. When fish consumption decreased to twomeals per month or less, the levels were consistent with background levels of those who do noteat fish.

For the purpose of analyzing the data, the frequency of consumption was grouped into threecategories (Table 8). Those who ate fish once a week or more had a statistically significanthigher blood mercury mean concentration (4.32 ppb) as compared to those with less frequentconsumption. Those with elevated blood mercury concentrations (>20 ppb) in this screening reported that they consumed fish at least once a week.

Table 8.

Mercury Concentration (ppb) by Frequency of Fish Consumption (Past Year)
Frequency of FishConsumption >Once /wk
(n=181)
1-2/month
(n=85)
<6 times/yr
(n=26)
Mean*4.321.82 2.08
Median*2.801.501.50
Range ofConcentrationsND - 35.10ND - 5.50ND - 8.70

* Calculations of mean mercury concentration and median include method detection limit (0.15) for samples which are non-detect.
ND- not detected

There were no elevated blood mercury levels detected in two sensitive populations - pregnantwomen or in any child less than seven years of age (Table 9 and Table 2). The mean bloodmercury concentration among pregnant women was 2.03 ppb. The mean mercury concentrationin children less than seven years of age was 2.15 ppb. No statistically significant differences inblood mercury by pregnancy status were observed in this screening. The third population ofconcern, commercial fishers and their families, contained an individual who had an elevated blood mercury level of 35.1 ppb (Table 3).

Table 9.

Mercury Concentration (ppb) by Pregnancy Status
Pregnancy Status Pregnant at the time of screening (n=52) Not Pregnant at screening or don't know (n =120)
Mean* 2.03 2.55
Median* 1.65 2.05
Range of Concentrations ND - 8.70 ND - 22.90

* Calculations of mean mercury concentration and median include method detection limit (0.15) for samples which are non-detect.
ND- not detected

Table 10 indicates that the blood mercury concentrations among pregnant women with recentfish consumption were not elevated when compared with pregnant women who did not eat fishin the recent past. The mean blood mercury concentration was 1.77 ppb in pregnant women whoate fish in the last three days compared to 2.13 ppb in pregnant women who did not eat fish inthe last three days. The reason for this difference is unclear and caution should be used ininterpreting these data and drawing conclusions. There are several factors to consider whichmight influence this result. First, the numbers of pregnant women were very small, making anyresults less stable. Second, though the women reported having eaten fish, the type and source ofthe fish eaten recently is unknown. Not all fish contain mercury. Third, since health educationalmaterials regarding fish advisories have targeted pregnant women, it is possible that women whodo consume fish are more careful about the type of fish and portion size which they consume. Finally, there are issues of recall errors which would lead to misclassification: a woman mayreport having eaten fish in the last three days, when she actually ate it more than three days ago, and the reverse, indicating eating fish more than three days ago when it was less than that.

Table 10.

Mercury Concentration (ppb) by Recent Fish Consumption in Pregnant Women
Recent Fish Consumption Ate fish in last three days (n=14) Did not eat fish in past three days or don't know (n =38)
Mean* 1.77 2.13
Median* 1.15 1.75
Range of Concentrations ND - 4.10 ND - 8.70

* Calculations of mean mercury concentration and median include method detection limit (0.15) for samples which are non-detect.
ND- not detected

Table 11 exhibits a summary of the six participants (five men and one female) who meet thescreening criteria for elevated blood mercury concentrations. Each of these individuals residedin either Morehouse or Ouachita parish. The range of blood mercury concentrations for theseparticipants was 19.6-35.1 ppb.The median blood mercury concentration for these individuals was 24.8 ppb.

Table 11.

Summary of Participants with Elevated Blood Mercury Concentrations
Mean: 25.93 ppb
Median: 24.8 ppb
Range: 19.6 - 35.1 ppb
SexParish of ResidenceConcentration (ppb)
MaleOuachita19.6
MaleMorehouse20.6
FemaleOuachita22.9
Male Ouachita26.7
MaleMorehouse30.7
MaleOuachita35.1


III. DISCUSSION

The monitoring of mercury concentrations in blood indicated that the majority of participants inthe screening services, including those in high risk groups, did not have elevated blood mercuryconcentrations. Six individuals however had levels greater than or equal to 20 ppb and wereadvised by the Louisiana Office of Public Health to decrease the consumption of fish caughtfrom the areas covered by the advisories. The six individuals with elevated blood mercuryconcentrations reside in parishes (Ouachita and Morehouse), which had the most participants inthe screening and that are adjacent to areas in Southern Arkansas that are also under healthadvisories for mercury contamination in fish.

Mercury is a ubiquitous contaminant which occurs throughout the world. Possible sources ofmercury to Louisiana's waters include atmospheric deposition, the alkali industry, naturalgeologic deposits and agricultural use as seed dressings. The most common form of organicmercury is methylmercury. It is produced by microscopic organisms in the soil and waterinteracting with metallic mercury; the more mercury present in the environment can increase theamount of methylmercury produced by these organisms. Humans may be exposed to mercury byeating fish contaminated with methyl mercury.

No pregnant women or children were found to have elevated levels. Their mean blood mercuryconcentration is comparable to the national background levels for those who do not eat fish. Nodata was collected to indicate the impact of the educational information previously distributed inassociation with the existing fish consumption advisories. The advisories and any related newsrelease generally emphasized the risk to target populations of pregnant women, children, andthose who consume large quantities of local fish.

Commercial fishermen and their households had the highest mean concentration of mercury inthis screening. Their blood mercury mean and median levels were significantly higher thanthose in other occupations. All the commercial fishermen and their household members whoparticipated in this screening are white. Efforts to provide additional educational information tocommercial fishermen and their household members should be increased.

Blood mercury concentrations tended to increase with age with those over 40 years old havingthe highest levels. Mean mercury concentrations were significantly lower in the 0-6 and 7-19age groups. Median mercury concentrations were also significantly lower in the 7-19 age group.

The survey questions that dealt with the frequency, location, and time of fish consumptiondemonstrate that blood mercury concentrations increased with fish consumption; however, notall the trends were statistically significant. Those who ate fish once a week or more had astatistically significant higher blood mercury mean concentration as compared to those with lessfrequent fish consumption. Mean blood mercury concentrations were significantly higher forthose who ate fish caught within 40 miles of their homes. Higher mean concentrations of bloodmercury were found in those who have eaten fish recently (within the last three days), althoughthis trend is not significant.

In addition, in this screening, blacks had a significantly lower mean concentration than whites.The mean blood mercury concentration increased as the educational level of participantsdecreased, although not significantly. Pregnant women who consumed fish in the past three dayshad significantly lower mean and median blood mercury concentrations than pregnant womenwho did not eat fish recently. No statistically significant differences in the blood mercury ofpregnant women and other women were observed in this screening.

Although the overall levels of mercury in blood remain relatively low in this screening group,the data tend to indicate that eating fish contributes to the mercury concentration in blood. Thiscross-sectional survey may or may not be generalized to other groups, because volunteers wereself-selected and information obtained was self-reported.


IV. CONCLUSIONS

Based on the blood screening data and information reviewed, LOPH concludes that:

  1. The overall blood mercury levels in participants are relatively low. Ninety-eightpercent of the participants exhibited blood mercury concentrations within the normallevels for people who eat fish. Individuals with high fish consumption have bloodmercury concentrations greater than those who do not eat fish.

  2. The blood mercury levels in participants do not indicate a public health hazard forthese individuals. The six individuals whose blood mercury levels were abovenormal were advised to decrease fish consumption. A public health hazard may existfor any individual who eats more fish than recommended in advisory areas.

  3. Pregnant women and children in this sample population have blood mercuryconcentrations comparable to national background levels. They also were found tohave lower blood mercury concentrations than others who participated in themonitoring.

  4. Commercial fishermen and their household members demonstrated the highest bloodmercury levels.

  5. Blood mercury levels tended to increase with age of the participant.

  6. The findings of this mercury screen may or may not be generalized to other individuals because the selection of the participants was not random.

V. RECOMMENDATIONS

  1. Continue the fish consumption advisories.

  2. Place additional emphasis on reaching higher risk groups with health educationactivities and the production of materials aimed at limiting fish consumption fromwaters where advisories are in place. The higher risk groups identified in thisscreening include commercial fishers and their families and older populations. Thisdoes not exclude previously identified sensitive populations, which include pregnantwomen and children.

  3. Disseminate the results of this health consultation with corresponding healtheducational materials in areas with fish advisories.

VI. REFERENCES

  1. Agency for Toxic Substances and Disease Registry. Toxicological Profile for Mercury. Atlanta: ATSDR, August 1997.

  2. Armstrong, M., Burge P, Evans, S, Giese, J, McChesney T, Nix J, Price A, ThorntonK, and Thurman D. Mercury in Arkansas: 1993-1994 Biennium Report, Chapter 2,June 1995.

  3. Burge, P, Evans, S. Mercury Contamination in Arkansas Gamefish: A Public HealthPerspective. Journal of the Arkansas Medical Society , Volume 90, Number 11, 542-544, April 1994.

  4. Ellenhorn, Matthew J. Ellenhorn's Medical Toxicology: Diagnosis and Treatment ofHuman Poisoning, (2nd Ed.). Baltimore: Williams and Wilkens, A WaverlyCompany, 1997.

  5. WHO. Environmental Health Criteria 101: Methylmercury, Geneva, World HealthOrganization, 106pp, 1990.

  6. Cochran, William G., Snedecor, GW. Statistical Methods, (8th Edition), Ames: Iowa State University Press, 1989.

VII. PREPARERS OF THE REPORT

Erica M. Caesar, M.S.P.H.

Kabrina Smith, M.S.

Margaret Metcalf, Sc.D.

LuAnn White Ph.D., D.A.B.T.

Elizabeth T.H. Fontham, Dr.P.H.

Dianne Dugas, M.S.W.

William Hartley, Sc.D.

Barry Kohl, Ph.D.

Frank Welch, M.D., M.S.P.H.

Louis Trachtman, M.D., M.P.H.

Barbara Cooper, M.S.P.H.


ATSDR Regional Representative

George Pettigrew
ATSDR Region 6


Technical Project Officer

William Greim
Division of Health Assessment and Consultation

Deborah Millette
Division of Health Studies
ATSDR
Atlanta, Georgia


CERTIFICATION

The Review of Blood Mercury Data for Selected Parishes in Louisiana Health Consultation wasprepared by the Louisana Office of Public Health under a cooperative agreement with the Agencyfor Toxic Substances and Disease Registry (ATSDR). It is in accordance with approvedmethodology and procedures existing at the time the health consultation was initiated.

William Greim
Technical Project Officer, SPS, SSAB, DHAC


The Division of Health Assessment and Consultation, ATSDR, has reviewed this healthconsultation and concurs with its findings.

Richard Gillig
Chief, SPS, SSAB, DHAC, ATSDR


VIII. APPENDICES

APPENDIX A:

LOUISIANA MERCURY CONTAMINANT FISHING ADVISORIES
FISH AND SHELLFISH CONSUMPTION HEALTH ADVISORIES PARISH LOCATION ISSUE DATE AREA
Pregnant women, breastfeeding women and children less than 7 years of age Other adults and children

No bowfin consumption.

Limit bass, bigmouth buffalo or freshwater drum to no more than 1 meal a month.

No bowfin consumption.

No consumption limits on other species.

St. Tammany, Washington Pearl River Issued 1/97 57 miles
Limit bowfin (choupique), flathead catfish, white crappie (sac-a-lait) or freshwater drum to no more than 1 meal a month. No consumption limits. Vermillion Seventh Ward Canal Issued 7/97 11.5 mi.
Limit bowfin, white crappie or largemouth bass to no more than 1 meal a month. No consumption limits. Desoto Toledo Bend Reservoir, north of Pine Island and south of Grand Cane Bayou Issued 11/17/97 not available

No bowfin consumption.

Limit crappie or largemouth bass to no more than 1 meal a month.

Limit bowfin to 2 meals a month. No consumption limits on other species. Sabine Toledo Bend Reservoir, San Patricio arm of the lake Issued 11/17/97 not available
Limit largemouth bass, flathead catfish, redear or bluegill sunfish (bream) to no more than 1 meal a month. No consumption limits. Vernon Lake Vernon Issued 8/97 6.6 sq. miles
King mackerel - 39 inches or less in total length Gulf of Mexico waters off of all costal parishes Gulf of Mexico Issued 9/4/97  
Limit consumption to one meal per month Limit consumption to four meals per month
King mackerel - greater than 39 inches in total length Gulf of Mexico waters off of all costal parishes Gulf of Mexico Issued 9/4/97  
NO consumption NO consumption
Limit bowfin (choupique) consumption to no more than one meal per month No consumption limits St. James, Ascension, Livingston, St. John the Baptist Blind River Issued 4/23/98  
Limit bowfin (choupique), black crappie or freshwater drum to no more than 1 meal a month No consumption limits. Acadia, Evangeline, St. Landry Bayou des Cannes Issued 10/97 54 mi.

No bowfin (choupique) consumption.

Limit largemouth bass, crappie (sac-a-lait) or freshwater drum (gaspergou) to no more than 1 meal a month.

Limit bowfin to 2 meals per month; no consumption limit on other species. Acadia, St. Landry Bayou Plaquemine Brule Issued 10/96 40 mi.

No bowfin (choupique) consumption.

Limit largemouth bass to no more than 1 meal a month.

Limit bowfin to 2 meals per month; no consumption limit on other species. Evangeline Chicot Lake Issued 5/97 3.1 sq. mi.

No bowfin (choupique) consumption.

Limit bass or crappie (sac-a-lait) to no more than 1 meal a month.

Limit bowfin to 2 meals per month; no consumption limit on other species. Natchitoches Black Lake Issued 10/96 7.6 sq. mi.

No bass consumption.

Limit other fish species to no more than 2 meals a month.

Limit bass to 2 meals per month; no consumption limit on other species. Ouachita, Union, Morehouse, Caldwell Ouachita River: LA/ARK border to lock at Columbia Issued 7/92; reviewed 8/94 102 miles
Limit largemouth bass, crappie (sac-a-lait) or freshwater drum (gaspergou) to no more than 1 meal per month. No consumption limits. St. Martin Henderson Lake Issued 1/96 37.8 sq. mi.
Limit all bass species or bowfin (choupique) to no more than 1 meal per month. No consumption limits. St. Tammany, Washington Bogue Chitto River Issued 8/96 35 miles
Limit largemouth bass, white crappie, black crapple, freshwater drum, redear sunfish to no more than 1 meal a month. No consumption limits. St. Tammany Bayou Liberty Issued 1/97 10 miles

Note: A meal is considered to be 1/2 pound in size.
Date issued - June 1998


APPENDIX B: LOCATIONS OF LOUISIANA PARISHES SELECTED FOR BLOOD MERCURY SCREENING

Locations of Louisiana Parishes Selected for Blood Mercury Screening


APPENDIX C: LOCATIONS OF LOUISIANA PARISHES WITH MERCURY CONTAMINANT FISHING ADVISORIES

Locations of Louisiana Parishes With Mercury Contaminant Fishing Advisories


APPENDIX D: LETTER FROM WILLIAM HARTLEY, SC.D. TO DIANNE DUGAS


Tulane University Medical Center
School of Public Health and Tropical Medicine
1430 Tulane Avenue
New Orleans, Louisiana 70112-2699
(504) 588-5374
FAX: (504) 584-1726




Date: October 24, 1997

From: William Hartley, Sc.D.

To: Dianna Dugas, MSW, MPH
Assistant Chief Epidemiologist
Louisiana Office of Public Health
Section of Environmental Epidemiology and Toxicology

Re: Blood Mercury

Mercury is a naturally occurring element. However, the greatest exposure to mercury comes from dietary intake, including consumption of contaminated fish. Most individuals will have some degree of mercury in their body regardless of personal fish consumption patterns. Recently, the International Commission on Occupational Health (ICOH) and International Union of Pure and Applied Chemistry (IUPAC) Commision on Toxicology determined that the mean background whole blood level for total mercury in people who do not eat fish is approximately 2 to 20 ppb (ATSDR 1994).

According to Ellenhorn's Medical Toxicology and Lexi-Comp's Clinical Reference, approximately 80 ppb total mercury in whole blood is considered to be the threshold limit for toxicity in adult males and adult non-pregnant females (Ellenhorn 1997 and Leiken 1995). For fetuses, 10-20 ppm of methylmercury in maternal hair, which corresponds to approximately 40 to 80 ppb methylmercury in the mother's blood, may result in a 5% risk of neurological and developmental abnormalities (WHO 1990). Therefore, mercury blood levels for pregnant women and children under seven years of age should be below 40 ppb.

Because the primary general population exposure to mercury is through consumption of fish, decreasing one's fish intake will decrease one's blood mercury concentration. Therefore, those individuals whose whole blood mercury levels are above the normal level of 20 ppb should decrease their consumption of fish until their blood mercury levels return to normal. Adults and children 7 years and older should seek medical evaluation if their blood mercury is greater than or equal to 80 ppb. Pregnant women and children less than 7 years should consult their physician if they have blood levels 40 ppb or higher. This level for pregnant women and children is based on the more toxic methylmercury and the screening levels are for total (all forms) mercury. Consequently, there is some additional safety in using >40 ppb as a screening level for total mercury.

The following table summarizes the recommended screening levels and public health actions for whole blood total mercury:

  Adults Pregnant Women and Children < 7yrs
Normal range 2-20 ppb 2-20 ppb
Recommend decrease fish intake > 20 ppb > 20 ppb
Advise medical evaluation by physician > 80 ppb > 40 ppb

References:
ATSDR, 1994. Toxicological Profile for Mercury. Agency for Toxic Substance and Disease Registry, U.S. Public Health Service. ATSDR/TP-93/10.

Ellenhorn, Matthew J. Ellenhorn's Medical Toxicology: Diagnosis and Treatment of Human Poisoning, (2nd Ed.). Baltimore: Williams and Wilkens, A Waverly Company, 1997.

Leiken, Jerrold B. Lexi-Comp's Clinical Reference Library Poisoning and Toxicology Handbook (2nd Ed.). 1996-1997. Frank P. Paloured, Pharm D., 1995.

WHO, 1990. Environmental Health Criteria 101: Methylmercury, Geneva, World Health Organization, 106pp.


APPENDIX E: PROTOCOL

DRAFT

December 17, 1997

Tentative Protocol to determine mercury concentrations in the blood of Louisiana citizens

I. Introduction

Testing of fish tissue from approximately 100 water bodies in Louisiana has indicated levels of mercury in the edible portions of fish sufficient to raise public health concerns. At this time fish consumption advisories for 12 water bodies across the state have been issued. Many other locations are scheduled for resampling due to the mercury levels found in initial sampling results. Although the levels of mercury in fish are gradually being documented, there has been no effort to determine if people who eat the fish are ingesting quantities of mercury which could cause adverse health effects. To date, the presence of advisories on the water bodies which contain the fish with the highest mercury concentrations has been presumed to enable residents to regulate their mercury intake. The best determination of levels of mercury in the citizens is to measure the amount of the metal in the body. Blood concentration is the superior biological media for the measurement of mercury ingested via fish tissue (ATSDR, 1994).

II. Proposal

The 1997 Lousiana legislature provided funding for the determination of levels of mercury in the blood of Louisiana citizens. The Louisiana Office of Public Health (LOPH) proposes to use the funding to offer, as a public service, free blood testing to state residents in three areas of the state where there are mercury advisories, the parishes around the Ouachita River, the Pearl River and Henderson Lake. The service will be provided throught the local Parish Health Units (PHUs). If anyone has an elevated blood mercury level, they will be advised to consult with their physician. Follow-up blood testing will be available.

A. Sub-populations

Infants, young children and pregnant or breast-feeding women are the groups within the general population most at risk due to the impact or mercury on the developing neurological system. Low income families possibly are more likely than others to use subsistence fishing to suppliment diet. Anecdotal information indicates that residents of some riverbank communities are consuming fish from advisory areas in excess of advised amounts. Therefore testing will be targeted to mothers and children 7 years and younger who live near three water bodies with advisories. These participants will be identified through their participation in the Women Infant and Children (WIC) federal assistance program. This program is directed at low income families. Participants will be offered this service in each of the 3 targeted areas. They will be asked to answer a questionnaire and have a blood sample taken.

Commercial fisherman, charter boat captains and their families have easy access to large amounts of fish and are likely to incorporate more into their diet than the general population. Therefore testing will be targeted at commercial fisherman and charter boat captains and their families in the three targeted areas in the state. Recruitment of this sub-population may be more difficult because commercial fisherman may not live in the same place that they work, they work variable hours and they do not frequent any central location where they can be interviewed and their blood sampled easily. The availability of this service i.e. location, times and dates that the service will be advertised through local press releases using T.V., radio and newspapers. LOPH is seeking to obtain the addresses of commercial fisherman and charter boat captains from LDWF so that letters can be sent to this population informing them of the service which is to be offered to them.

The service will also be available to the general public. This service will be offered at a minimum of 3 PHU in the targeted areas for a limited time. Depending on the amount of community response, the service will be offered at other PHUs within the same or additional advisory areas until the funding is exhausted. The service will be publicized and offered at one site at a time based on site prioritization and as money permits.

B. Notification of Results

The International Commission on Occupational Health and International Union of Pure and Applied Chemistry, Commision on Toxicology determined that the mean background whole blood level for total mercury in people who do not eat fish is approximately 2 ppb. Normal total mercury blood levels range from 2 to 20 ppb (ATSDR, 1994).

The following table summarizes the recomended screening levels and public health actions for whole blood total mercury.
  Adults Pregnant Women and Children less than 7 years of age
Normal range 2-20 ppb 2-20 ppb
Recommend decreased fish intake >20 ppb >20 ppb
Advise medical evaluation by physician > 80 ppb > 40 ppb

Each client who gets a blood test will receive a letter with their blood mercury concentration. In the event that a person's blood mercury concentration is determined to be mildly elevated, (greater than 20 ppb and less than 80 ppb), or, for pregnant women and children less than 7 years of age, (greater than 20 ppb and less than 40 ppb), LOPH will notify the client through the mail and offer recommendations on how the level could be reduced by decreased fish intake. Persons whose blood has a mercury concentration of 80 ppb or greater and pregnant women and children whose blood has a mercury concentration of 40 ppb or greater will be advised to decrease fish intake and seek the advice of a physician. A retest after 3 months will be available to those with elevated blood mercury levels.

C. Site selection for site specific portion of testing

Identification of blood mercury levels in persons at high risk, those who consume the most fish or are within the most susceptible sub-population (pregnant and breast-feeding women, fetuses, young children), is the goal of the blood testing service. Therefore, the selection of sites for offering this service is an important factor.

The occurrance of mercury in fish and fish consumption advisories is not restricted to any one area of the state but is distributed across the state including rivers, bayous, inland reservoirs and coastal lakes. Blood testing will be offered in a minimum of three locations within the State. Depending upon the level of participation, additional locations will be added until the funds are exhausted.

The following criteria are used to identify three locations where the blood mercury service is to be offered.

  1. Nearby water body under an LOPH fish consumption advisory.
  2. High mercury concentration in fish in comparison to other locations under advisement.
  3. Low median annual income in comparison to the State average.

The first location which has met the above criteria is in the vicinity of the Ouachita River, in the northeast portion of the state in Morehouse, Union, Caldwell and Ouachita parishes. The first mercury advisory released in the state was for the Ouachita River in 1992. Some of the highest mercury concentrations have been found at this location. The second location will be in Region IV in St. Martin, Acadia, Lafayette, St. Landrey and Evangeline parish. This area has 4 advisories. The third location will be Washington and St. Tammany parishes where the Pearl River serves as the eastern state border. There are two additional consumption advisories in this portion of the state so individuals could be getting mercury from more than one water body. The specifics of the advisories are as follows.

LOCATION PARISH Advice for women planning to become pregnant, pregnant women, breast-feeding women, and children less than 7 years of age Advice for other adults and children AREA
Ouachita River: LA/ARK Border to lock at Columbia Ouachita, Union, Morehouse, Caldwell

No bass consumption.

Limit other fish species to no more than 2 meals a month.

Limit bass to 2 meals per month; no consumption limit on other species. 102 miles
Bayou Plaquemine Brule Acadia, St. Landry

No bowfin (choupique) consumption.

Limit largemouth bass, crappie (sac-a-lait) or fresh water drum (gaspergou) no more than 1 meal a month

Limit bowfin to 2 meals per month; no consumption limit on other species. 40 mi.
Chicot Lake Evangeline

No bowfin (choupique) consumption.

Limit largemouth bass to no more than 1 meal a month

Limit bowfin to 2 meals per month; no consumption limit on other species. 3.1 sq. miles
Bayou des Cannes Acadia, Evangeline, St. Landry Limit bowfin, black crappie or freshwater drum to no more than 1 meal a month No consumption limits 54 mi.
Henderson Lake St. Martin Limit largemouth bass, crappie (sac-a-lait) or freshwater drum (gaspergou) to no more than 1 meal per month. No consumption limits. 37.8 sq. mi.
Bogue Chitto River St. Tammany, Washington Limit all bass species or bowfin (choupique) to no more than 1 meal per month. No consumption limits. 35 mi
Bayou Liberty St. Tammany Limit largemouth bass, white crappie, black crappie, freshwater drum or redear sunfish to no more than 1 meal a month. No consumption limits. 10 mi.
Pearl River St. Tammany, Washington

No bowfin consumption.

Limit bass, bigmouth buffalo or freshwater drum to no more than 1 meal a month.

No bowfin consumption.

No consumption limits on other species.

57 miles

D. Questionnaire Administration

Upon arrival at the test location, each client will be read a consent form which they must sign. The client will then be read a questionnaire by a nurse. The questionnaire will contain questions designed to gather information about their mercury exposure as it relates to fish consumption practices. Although this questionnaire will provide some background information on fish consumption in Louisiana, the data will not be sufficient to completely characterize the issue nor draw definitive conclusions. Information on the geographic source, species, amount and frequency of fish meals will be gathered. Sources of other mercury exposure such as through occupational exposure, pharmacological use or personal hobby possibly may be identified through the questionnaire. Approval of the questionnaire and corresponding instructions (found in the attachments) from the LOPH Forms Committee is likely to be the task requiring the most time before the service can be offered. A tele-conference will be scheduled to train the nurses about the questionnaire.

No one who requests a blood test will be denied, even if the questionnaire response indicates low fish consumption rates.

E. Specimen collection, transport and analysis

After the nurse has completed the questionnaire on the client, a phlebotomist or nurse at the PHU or other location will take the blood sample. A 2.5 ml sample of venous blood will be submitted in a lavender top tube. The specimens should be labeled, preserved, and transported following the same procedures used for blood lead samples which are collected at the PHUs. Refer to the Louisiana Public Health Laboratories Specimen Submission Manual (page 12). The specimens will be shipped to the Central Laboratory in New Orleans for analysis. Samples of other media used to indicate mercury exposure such as hair, fingernails, urine or breast milk will not be accepted at this time.

The blood specimens will be analyzed in batches by cold vapor atomic absorption spectrometry. In this method the mercury is reduced to elemental state. Therefore total mercury concentration rather than speciated mercury will be provided.

III. Limitations

Participation is to be voluntary. Therefore, the sample population will be self-selected and may not represent the general population in the areas where fish advisories exist. The WIC women and children population sampled is limited to WIC participants. Other pregnant women, infants and young children who are not on WIC will only be captured if they select to come to a PHU or go to the Mall during the Health Fair. Likewise, the subsistence or recreational fisherman are self selected and are more likely to be those who are well informed, educated about health effects of mercury and have the free time and transportation to get to the PHU.

Ingestion of commercial fish meals such as canned tuna will contribute as will certain occupational exposures to blood mercury levels. The questionnaire will include brief questions on these two sources of exposure.

The interpretation of the blood results is completely dependent upon the clients accurate response to the questionnaire. The reliability of the information gathered by the questionnaire will depend upon an individual's ability to recall past meals. Information on both the source of the fish and the species is needed.

Following ingestion, mercury levels in the blood peak at approximately 30 hours. Mercury in the body has a half life of 60-70 days. A high level could be the result of a recent meal, not a chronically high blood level. Likewise a low level could be the result of a temporary sessation of fish consumption. In some cases, a fraction of the ingested mercury can be stored in the brain for a long time. This cross-sectional survey functions as a community service and the results may serve to indicate a need for additional surveillance.

IV. Findings of Expected (Outcome) Conclusions:

This community service is being provided to citizens in areas where LOPH fish advisories exist to ensure that concerned people who feel they are at risk for mercury exposure have a resource to get tested. It is not intended to provide a complete description of the problem nor the actual level of mercury exposure in these communities.


APPENDIX F:

LOUISIANA MERCURY IN FISH BLOOD SCREENING PROGRAM TIMES AND LOCATIONS
Location Weekdays Saturday Address/Phone
Acadia Parish
Health Unit
Call unit for information.   530 E. Mill St.
Crowley
318-788-7507
Caldwell Parish
Health Unit
March 3-6,
8 a.m.-3:30 p.m.
March 7,
8 a.m.-2 p.m.
200 Collins Rd.,
Columbia
318-649-2393
Evangeline Parish
Health Unit
Call unit for information.   415 W. Cotton St.
Ville Platte
318-363-1135
Iberia Parish
Health Unit
Call unit for information.   121 W. Pershing St.
New Iberia
318-373-0021
Jefferson Davis Parish
Health Unit
March 4, Mar 5, March 6,
1:30-3:30 p.m.
  403 Baker St.
Jennings
318-824-2193
Lafayette Parish
Health Unit
Call unit for information.   2100 Jefferson St.
Lafayette
318-262-5616
Morehouse Parish
Health Unit
March 3-6,
8 a.m.-4:30 p.m.
March 7,
8 a.m.-2 p.m.
650 School Rd.,
Bastrop
318-283-0806
Ouachita Parish
Health Unit
(Monroe)
March 3-6,
8 a.m.-4 p.m.
Feb. 28 and March 7,
8 a.m.-2 p.m.
2913 Desiard St.,
Monroe
318-362-3400
Ouachita Parish
(West Monroe)
March 3-6,
8 a.m.-4 p.m.
Feb. 28 and March 7,
8 a.m.-2 p.m.
1416 Natchitoches St.,
West Monroe
318-362-3428
Ouachita Parish
Sterlington Hospital
Emergency Room
March 2-3,
8 a.m.-2 p.m.
  Sterlington
318-665-2771
St. Landry Parish
Health Unit
Call unit for information.   308 W. Bloch St.
Opelousas
318-948-0220
St. Martin Parish
Health Unit
Call unit for information.   415 St. Martin St.
St. Martinville
318-394-3097
St. Tammany Parish
Health Unit
March 2-6,
8-10 a.m.
Feb. 28 and March 7
9-11 a.m.
520 Old Spanish Trail
Slidell
504-646-6446
Vermillion Parish
Health Unit
Call unit for information.   401 S. St. Charles St.
Abbeville
318-893-1443
Washington Parish
Health Unit
(Franklinton)
March 2-6,
8-10 a.m.
Feb 28,
9-11 a.m.
1104 Bene St.,
Franklinton
504-839-5646
Washington Parish
Health Unit
(Bogalusa)
March 2-6,
8-10 a.m.
March 7,
9-11 a.m.
626 Carolina Ave.
Bogalusa
504-732-6615


APPENDIX G: PARTICIPANT QUESTIONNAIRE

Questionnaire page 1

Questionnaire page 2


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