Interpreting reports of Blue Green Algae at Lake Texoma 2012
A primer for the recreational user of the lake
Scott Miller – Student - Ph.D., Public HealthWalden University - PUBH-8165-1Instructor: David Anderson, Ph.D.Spring Term, 2012
Photo – Scott Miller
Educational Objectives
• Inform recreational users of Lake
Texoma regarding the recent reports
of cyanobacteria, also referred to as
Blue Green Algae (BGA)
• Address the conflicting guidance from
The U.S. Army Corps of Engineers and
The Grayson County Health
Department
• Recreational users will have more
information to make decisions
regarding the recreational use of Lake
Texoma Photo – Scott Miller
Persons/Groups affected by BGA Reports at Lake Texoma
Background and Current Status
• August, 2011o Various media outlets inform the public on U.S. Army Corps of
Engineers (USACE) reports that BGA levels render Lake
Texoma “unsafe” (Liu, 2011)
o USACE issued a Warning (forbidding contact with the lake) for
portions of Lake Texoma, and placed the entire lake on
Advisory, discouraging lake contact ("BGA update," 2011)
Liu, X. (2011, August 26). Blue-Green Algae Found At Lake Texoma, Water Contact Prohibited. News9.com. Blue-green algae update. (2011). Retrieved from http://www.swt.usace.army.mil/~news/NewsDetail.CFM?ID=589
Background and Current Status, continued 2• Winter 2011 – Spring 2012
o USCAE updates BGA Warning to lake-wide “Advisory” ("Update
12-1-11," 2011)
o April 6, 2012 - USCAE maintains BGA Advisory at Lake Texoma
("March 28," 2012)
• Advisory signs are posted at boat ramps and other places of
public access to Lake Texoma
Lake Texoma BGA update 12-1-11. (2011). Retrieved from http://www.swt.usace.army.mil/~news/NewsDetail.CFM?ID=615
Lake-wide advisory still in place at Lake Texoma; samples taken March 28. (2012). Retrieved from http://www.swt.usace.army.mil/TDR/eNewsStory.cfm?Number=1617
Background and Current Status, continued 3• February 2012
o “Lake Texoma is Open for Business” (Dixon, 2012) • Educational campaign introduced by Grayson County
“Officials” with support from the Lake Texoma Association
• Statements from the “Open for Business” campaign appear to
undermine the USCAE’s educational campaign regarding BGA
• “Chris Duroy is a Marshall County Commissioner. He says last
year's Corps of Engineers warnings scared people from
spending time on the lake.” (Dixon, 2012, para. 6) Dibusiness”. KXII.com. Retrieved from http://www.kxii.com/community/headlines/Grayson_County_Officials_Said_Lake_is_open_for_Business__138525689xon, K. (2012, February 1). Grayson Co. officials say Lake Texoma is “open for.html
Background and Current Status, continued 4• Local business suffer as a result of the BGA warning and a severe
drought
o One marina, reported that at a time when boats should be
launching at a rate of 6 per fifteen minutes, only six boats
entered the water the entire day (Dixon, 2012, para. 3)
• Grayson County Health Department releases a “Blue-Green Algae
Risk Communication Tool” with updated BGA test results from
Lake Texoma (Grayson County Health Department, 2012) Dixon, K. (2012, February 1). Grayson Co. officials say Lake Texoma is “open for business”. KXII.com. Retrieved from http://www.kxii.com/community/headlines/Grayson_County_Officials_Said_Lake_is_open_for_Business__138525689.htmlGrayson County Health Department. (2012). Blue-Green Algae Sampling Data. Grayson County, TX: Grayson County Health Department.
Background and Current Status, continued 5• The USCAE maintains a lake-wide Advisory discouraging contact
with the water of Lake Texoma but maintains that fish may be
consumed if handled properly
• The Lake Texoma Association and Grayson County Health
Department highlight that no reports of adverse human health
effects caused by BGA have been reported subsequent to contact
with the water of Lake Texoma (Grayson County Health
Department, 2012)
• The public, is receiving conflicting messages from Government
agencies, creating confusion in the mind of the recreational user of
Lake TexomaGrayson County Health Department. (2012). Blue-Green Algae Sampling Data. Grayson County, TX: Grayson County Health Department.
What is cyanobacteria and can it harm humans?• Cyanobacteria, also known as blue-green algae, is present in most
lakes in Texas but does not typically present as a threat to humans
o Common descriptions for BGA overgrowth include:• “Pond Scum”• “Stagnant Water”
• Harmful Algae Blooms (HAB’s) occur when conditions permit the blue-
green algae to overgrow other species of aquatic life ("HAB’s," n.d.)
o Causes• Abundant nutrients for BGA, excess nitrogen and phosphorous• Change in lake conditions, i.e., excess sunlight, stagnant water,
high heat
Harmful Algal Blooms (HABs). (n.d.). Retrieved from http://www.tpwd.state.tx.us/landwater/water/environconcerns/hab/
BGA is a threat to human health
• BGA can produce cyanotoxins (Carmichael et al., 2001)
o Neurotoxic anatoxin-a, anatoxin-a(s), saxitoxins, others
• Human poisonings are rare as most people avoid water that has
“pond scum” or a foul odor, which is typical of a HAB
• Water treatment / filtration remediates the threat to human
health
• BGA and its toxins may be ingested by mouth or via inhilation
• Humans have died as a result of exposure to BGA cyanotoxins
o Symptoms include a mild rash through liver toxicity resulting in
deathCarmichael, W. W., Azevedo, S. M., An, J., Molica, R. J., Jochimsen, E. M., Lau, S.,...Eaglesham, G. K. (2001, July). Human Fatalities from Cyanobacteria: Chemical and Biological Evidence for Cyanotoxins. Environmental Health Perspectives, 109 (No. 7), 663-668. Retrieved from http://ehp03.niehs.nih.gov/article/fetchArticle.action?articleURI=info%3Adoi%2F10.1289%2Fehp.01109663
BGA is a threat to human health, 2
• BGA may be associated with neurodegenerative conditions (Holtcamp,
2012)
o Only 5-10% of ALS (Lou Gehrig’s disease) and Parkinson Disease are
due to an inherited genetic mutation, suggesting a role for
environmental causes of these diseases (Holtcamp, 2012, p. A113)
o Cyanotoxins have been found in the brains of people with ALS and
Parkinson Disease, these toxins cause human neurons to undergo
apoptosis (cell death) (Holtcamp, 2012, p. A114)
• Cyanotoxins in the brain do not necessarily mean causality for
neurodenerative conditons, more study is needed (Holtcamp, 2012, p.
A115) Holtcamp, W. (2012, March 1). The Emerging Science of BMAA: Do Cyanobacteria Contribute to Neurodegenerative Disease? Environmental Health Perspectives, 120 (No. 3), A110-A116. doi:10.1289/ehp.120-a110
WHO guidelines regarding BGA (World Health Organization [WHO], 2003, p. 150)
• Low Probability for adverse health effects (based on cell counts in water)o Skin irritation, GI illness. Post Warning Signs onsite to Inform Public.
• Moderate Probability for adverse health effects (based on cell counts in
water)o Potential for adverse short and long term health outcomeso Watch for “scum” on watero Discourage water contact, Post onsite signs, Inform relevant authorities
• High Probability for adverse health effects (based on cell counts in water)o Documented human or animal disease from siteo Potential for acute poisoning & Immediate action to stop water contact
World Health Organization. (2003). Guidelines for safe recreational water environments - Volume 1 - Coastal and Fresh Waters [Issue Brief]. Retrieved from WHO website: http://www.who.int/water_sanitation_health/bathing/srwe1/en/
Conflicting Messages, Uncertain Risks
o HAB occurred in Lake Texoma in 2011 and BGA toxins remain in
Lake Texoma currently• USCAE currently discourages contact with the water based on
the published standards of the World Health Organization• Grayson County Health Department, utilizing different criteria,
suggests there is very little risk associated with water contact– Grayson County has a vested reason to encourage people to
utilize the lake and has received pressure from the business community to react to the USCAE Warnings and Advisory
– Grayson County has undertaken more extensive and precise testing on the water of Lake Texoma
– Grayson County sponsored testing, reveals low levels of cyanotoxins (Grayson County Health Department, 2012)
Grayson County Health Department. (2012). Blue-Green Algae Sampling Data. Grayson County, TX: Grayson County Health Department.
Summary
• BGA and associated toxins, have been found in Lake Texoma
• BGA toxins (cyanotoxins) are capable of causing mild human
diseases such as a rash, GI disturbance or may cause death
• USCAE and Grayson County Health Department have each issued
conflicting guidance for the recreational user of Lake Texoma
o WHO Standards v. “newer” standards produced by an outside
lab but sponsored by The Grayson County Health Department
• Advisory Signs warning of BGA are still present at Lake
Texoma and the USACE currently advise against water
contact
Summary, 2
• Grayson County Health Department and other County Officials,
provide information that the public may use the lake with
reasonable caution
o Grayson County has economic motives to encourage Lake
Texoma visits
o No documented cases of adverse human health have been
reported as a result of exposure to the water of Lake Texoma
• Reporting bias?
Summary, 3
• Interpreting the data from two Government agencies should not
require such a detailed examination of the sources and
methodologies used to make public guidance
• The data seem to indicate that contact with Lake Texoma is safe,
provided that the public avoid areas that are grossly
contaminated with BGA
o Only a detailed examination of the USCAE report would
indicate where the highest concentrations of BGA have been
found at Lake Texoma
o Avoid stagnant water and water with a “scum” on the surface
More information regarding Blue-Green Algae and risks to human health
• The OPTIONAL link below will direct to a short video
presentation on BGA produced by the State of Ohio to
inform residents on dangers and precautions relating to
BGA exposure
http://powerhost.powerstream.net/008/00153/HarmfulAlgalBl
ooms.wmv
• WHO Guidance on BGA
Chapter 8 - Algae and cyanobacteria in fresh water pdf
ReferencesBlue-green algae update. (2011). Retrieved from http://www.swt.usace.army.mil/~news/NewsDetail.CFM?ID=589
Carmichael, W. W., Azevedo, S. M., An, J., Molica, R. J., Jochimsen, E. M., Lau, S.,...Eaglesham, G. K. (2001, July).
Human Fatalities from Cyanobacteria: Chemical and Biological Evidence for Cyanotoxins. Environmental Health
Perspectives, 109 (No. 7), 663-668. Retrieved from
http://ehp03.niehs.nih.gov/article/fetchArticle.action?articleURI=info%3Adoi%2F10.1289%2Fehp.01109663
Dixon, K. (2012, February 1). Grayson Co. officials say Lake Texoma is “open for business”. KXII.com. Retrieved
from
http://www.kxii.com/community/headlines/Grayson_County_Officials_Said_Lake_is_open_for_Business__138525689.
html
Grayson County Health Department. (2012). Blue-Green Algae Sampling Data. Grayson County, TX: Grayson
County Health Department.
Harmful Algal Blooms (HABs). (n.d.). Retrieved from
http://www.tpwd.state.tx.us/landwater/water/environconcerns/hab/
References
Holtcamp, W. (2012, March 1). The Emerging Science of BMAA: Do Cyanobacteria
Contribute to Neurodegenerative Disease? Environmental Health Perspectives, 120 (No.
3), A110-A116. doi:10.1289/ehp.120-a110
Lake Texoma BGA update 12-1-11. (2011). Retrieved from
http://www.swt.usace.army.mil/~news/NewsDetail.CFM?ID=615
Lake-wide advisory still in place at Lake Texoma; samples taken March 28. (2012).
Retrieved from http://www.swt.usace.army.mil/TDR/eNewsStory.cfm?Number=1617
References
Liu, X. (2011, August 26). Blue-Green Algae Found At Lake Texoma, Water Contact
Prohibited. News9.com. Retrieved from http://www.news9.com/story/15340346/blue-
green-algae-found-in-lake-texoma-water-contact-prohibited
World Health Organization. (2003). Guidelines for safe recreational water environments
- Volume 1 - Coastal and Fresh Waters [Issue Brief]. Retrieved from WHO website:
http://www.who.int/water_sanitation_health/bathing/srwe1/en/
World Health Organization. (2003). Guidelines for safe recreational water environments
- Volume 1 - Coastal and Fresh Waters [Issue Brief]. Retrieved from WHO website:
http://www.who.int/water_sanitation_health/bathing/srwe1/en/