Cyanobacteria: Blue-green algae poisoning threatens livestock

Here is an article with a good picture of cyanobacteria. I don’t have confidence with their descrption of where it can be found in water or how it should be treated. I also don’t have confidence recommending which country is an expert on cyanobacteria. I do have confidence stating there are huge gaps internationally regarding cyanobacteria so extreme caution should be used both in how to identify it and treat it. Here is a report report74_management_strategies_BGA (2)  from Australia that I think is worth reading – even it recommends consulting a cyanobacteria expert and another website that gives good information about cyanobacteria species. I’m not a scientist, I just like to read and find conflicting information so please consult with an expert on this topic rather than follow my ramblings. Thanks.

 

By NDSU

Blue-green algae is visible on water in the Devils Lake area. Blue-green algae can pose a health threat to livestock and wild animals.

Several livestock deaths have been attributed to blue-green algae poisoning in North Dakota recently, putting livestock producers and veterinarians on alert.

Cases usually occur in late summer or early fall, when stagnant ponds and the right nutrient conditions allow for overgrowth of algae, according to Gerald Stokka, North Dakota State University Extension veterinarian and livestock stewardship specialist. However, this spring’s mild weather and warm water have been ideal conditions for algae blooms to occur.

Blue-green algae, also known as cyanobacteria, typically grow in stagnant, warm pond water. When the algae die, they produce a toxin that is poisonous to most livestock and wildlife, including ducks, geese, rabbits, muskrats, frogs, fish and snakes.

Under favorable conditions, blue-green algae can double in number in 24 hours, and these blooms can turn pond water blue to brownish green.

“A close watch for unexplained livestock deaths is important,” Stokka says. “Consult a veterinarian to find a cause of death so steps can be taken to prevent additional livestock deaths.”

He also urges producers to take note of any dead wildlife around bodies of water because that could be an indication of blue-green algae in the water. The algae flourish only in the top few inches of water, so toxic concentrations typically are found just in small ponds where waves don’t mix the water thoroughly. Blue-green algae blooms do not occur in lakes and rivers.

A veterinarian can help determine if a particular pond has toxic concentrations of the algae, Stokka says.

Another option is to send a water sample to the NDSU Veterinary Diagnostic Laboratory. The lab also can diagnose a blue-green algae problem in dead animals if someone sends a liver sample. For more information on how to submit samples, contact the lab at (701) 231-7527 or (701) 231-8307, or visit its website at http://www.vdl.ndsu.edu/.

If a pond contains toxic concentrations of blue-green algae, keep animals from drinking the water by fencing off the pond and providing another source of water. Because the toxins are concentrated at the surface, water may be pumped from the bottom of deep sloughs or potholes to watering tanks.

Generally, toxic algae blooms last only a few days, but they may persist for several weeks.

Small ponds that don’t drain into other waterways or bodies of water may need to be treated with copper sulfate or an algicide. Stokka recommends a treatment rate of 2 pounds of copper sulfate per acre-foot of water. That approximates a rate of 8 pounds per 1 million gallons.

Toxin levels increase immediately after treatment, so livestock should not be allowed to drink from treated ponds for a week.

For more information on detecting blue-green algae and protecting livestock from its toxins, contact your county office of the NDSU Extension Service. Ask for the publication “Cyanobacteria (Blue Green Algae) Poisoning.”

 

 

Cyanobacteria: It’s Easier Being Green Than Blue-green

The Oregon Health Authority gives a much simpler definition of algae for those of us who aren’t plant biologists. Click here for the full article or read an excerpt below.

 

Kermit the frog sang the song “It isn’t easy being green” lamenting the troubles of being a frog. The blue-green I am referring to is blue-green algae. What is it and why should you care? First things first. According to Dictionary.com “algae are any of numerous groups of chlorophyll-containing, mainly aquatic eukaryotic organisms ranging from microscopic single-celled forms to multicellular forms 100 feet (30 meters) or more long, distinguished from plants by the absence of true roots, stems, and leaves and by a lack of nonreproductive cells in the reproductive structures: classified into six phyla Euglenophyta, Crysophyta, Pyrrophyta, Chlorophyta, Phaeophyta, and Rhodophyta. Blue-green algae are defined as “a widely distributed group of predominantly photosynthetic prokaryotic organisms of the subkingdom Cyanophyta, resembling phototrophic bacteria, occurring singly or in colonies in diverse habitats: some species can fix atmospheric nitrogen.” it is also called Cyanobacteria.

The Oregon Health Authority gives a much simpler definition of algae for those of us who aren’t plant biologists. They say “algae are microscopic plants that grow naturally in oceans and fresh water. Under certain conditions, some algae can grow into a large visible mass called a bloom.” The blue-green is one of the algae that produces toxins (poisons) that can cause serious illness or death in humans and even pets, wildlife, and livestock.

What does an algae bloom look like? Scientists describe blooms as looking like a scum or foam on the surface of the water that can appear in various colors such as white, brown, green, or in this case blue-green. Don’t let that fool you though because you can’t tell whether what appears to be an algae bloom is toxic or not just by looking at it. The water has to be tested to be sure. If the surface of a pond, lake, or reservoir looks suspicious to you (doesn’t aways look as green as the picture above) it’s better to stay out of direct contact with the water.

You might remember that last summer there were some blue-green algae advisories throughout Western Oregon which included Walterville Pond, Dorena Reservoir, Dexter Reservoir, and Tenmile Lake in Coos County. The one issued for Dexter Reservoir could not have come at a worse time considering it was issued July 3rd. just one day before crowds of people gathered along the shore for a 4th of July celebration with entertainment, food, and fireworks sponsored by the Dexter Volunteer Fire Department and the Lowell Volunteer Fire Department in conjunction with Eugene Daily News.

Despite the advisory some folks did go into the water and I know I saw a couple of dogs frolicking and splashing near the shore. I don’t know if anyone got sick, but they were taking an unnecessary risk. Being near the water or even boating, as long as you don’t get a heavy spray of water hitting the boaters, is not a problem. You must have direct contact with contaminated water. “Skin irritation or rash is the most commonly reported health effect. Other symptoms range from diarrhea, cramps and vomiting to fainting, numbness, dizziness, tingling and paralysis. The most severe reactions occur when large amounts of water are swallowed. The chronic effects of long-term exposure to algae toxins are being studied.”

If you enjoy a picnic, camping, or boating near area lakes and reservoirs you should make sure the water is not going to harm you, your family, or your pets.

Canada`s lack of drinking water standards: Fracking waste water being injected into old wells in northeastern B.C.

This is not safe at all. Does our government and elected leaders understand that our Human Rights are at risk? Water.ca reports “there are literally thousands of different water systems in British Columbia—more than 3,000 public and community water systems under provincial jurisdiction and 468 small First Nations water systems under federal jurisdiction. While water systems share some common features, individual water systems are designed in different ways and will face specific issues and challenges.”  Here is a ijerph-11-04634 (2) Drinking Water Quality Guidelines across Canadian Provinces 2014 that states more research is required due to the high degree of variability in drinking water management and oversight capacity between urban and rural areas. While research is recommended our water is being contaminated due to the lack of consistent drinking water standards across Canada. Add global warming and fracking to the mix and we have a recipe for disaster of unknown proportions. If you know of any other reports that should be archived, please forward it to me through a Comment below; I would be very grateful for your help. Sorry, I had quite a few problems getting this document to look and read correctly so I`ve given up. Please read it though. Thanks.

In this Action Plan for Safe Drinking Water in British Columbia  report dated 2002 it states:

There are more than 3,300 water systems in BC:

British Columbia’s Water Systems

There are more than 3,300 water systems in B.C. The 96 systems

operating in large municipalities serve close to 90 per cent of the

population. The remaining 10 per cent of the population is served

by a variety of public and private systems:

 • Small municipalities (57 systems);

 • Regional district service areas (97 systems);

 • Improvement districts (211 systems);

 • Private water utilities (185 systems);

 • Water users communities (118 systems);

 • First Nation reserves (468 systems);

 • Individual private wells and domestic licensees (est. 63,000);

 • Others including Crown Corporations, industrial operations,

 BC Parks and private campgrounds, mobile home parks,

 restaurants and service stations (estimated 2100 systems).

Approximately 2,000 systems have fewer than 15 connections

 

Based on the conflicting number of water systems reported below, I don’t believe the BC Government has any idea how many water systems we have in BC. If that is true, then how can they have control over the safety of our water?

In this report waterreport08_web BC Govt of Health report titled Progress on the Action Plan for Safe Drinking Water dated 2008 dated 2008 it states there are over 4,591 different water systems in BC and 945 on Vancouver Island.

In this reported drinking-water-report-2011 Progress on the Action Plan for Safe Drinking Water in BC 2011 dated 2011 states there are 4,550 water systems in BC and 746 on Vancouver Island.

 

I have been watching the boil water advisories in Powell River who installed a water treatment system a few years ago and still have too many boil water advisories for my comfort level. Why is that?

 

 

In this report dated 2004 titled Please Hold – A Report on Diminished Monitoring and Enforcement Capacity in the Ministry of Water, Land and Air Protection it states:

“there are 320 human icons on this report’s front cover. Each
represents a public servant who lost his or her job with British Columbia’s
Ministry of Water, Land and Air Protection over the past three years. Colour
changes signify job losses in a new job category. The large mass of 128
purple icons on the bottom half of the page, for example, corresponds to
the 128 Scientific Technical Officers whose jobs were lost. For a complete
breakdown of job losses by category see page eight of this report.”

The above report further states:

Viewed in isolation, the cutbacks to the Ministry of Water, Land and Air
Protection may seem dramatic. When recent history is considered, however,
they take on added gravity.

Drawing on payroll and budget data from the provincial government it is
possible to arrive at figures on just how many people and/or full-time
equivalent positions were dropped from the public payroll over the past
decade.

Two ministries where substantial cuts occurred were MWLAP’s predecessor,
the Ministry of Environment, Lands and Parks (MELP), and the Ministry of
Forests (MOF). Payroll data shows that between the years 1991 and 1996
employment in both ministries rose considerably. But from 1996 through
2000 employment levels steadily dropped.4

The number of regular MOF employees fell nearly 17 per cent from 4,590 to
3,823. In MELP the cuts were deeper, amounting to an even 22 per cent,
with the number of regular employees falling steadily from 2,336 in 1996 to
1,823 by 2000.

It also has a table which I’ve cut & paste below and states:

Two ministries where substantial cuts occurred were MWLAP`s predecessor, the Ministry of Environment, Lands and Parks (MELP), and the Ministry of Forests (MOF). … MELP was subsequently split into two ministries – MWLAP and the Ministry of Sustainable Resource Management or MSRM.

Cuts resulted in employment declines by:

MWLAP 29.8%

MSRM 50.4%

MOF 27.9%

DATE MWLAP MSRM MOF

July 2001 1,317 FTEs 1,519 FTEs 4,083 FTEs
(1st Liberal budget)
Feb. 2004 924 FTEs 754 FTEs 2,942 FTEs
(latest budget)
Total Lost 393 FTEs 765 FTEs 1,141 FTEs
Percentage Decline 29.8 % 50.4 % 27.9 %

I strongly recommend reading the whole report to understand how these cuts are going to affect us with respect to fracking in BC.

 

 

Here is another report from our Ombudsman dated 2008 that is well worth reading too.

http://www.wsabc.ca/wp-content/uploads/2011/04/Ombudsmans-Report-on-Drinking-Water.pdf

 

Acknowledgements:

Click to access Ombudsmans-Report-on-Drinking-Water.pdf

Click to access waterreport08_web.pdf

http://www.water.ca/wkd-guide-drink-water-1.asp#bc

Click to access safe_drinking_printcopy.pdf

http://www.vancouversun.com/health/Fracking+waste+water+being+injected+into+wells+northeastern/9942146/story.html
http://www.un.org/en/documents/udhr/
ijerph-11-04634 (2) Drinking Water Quality Guidelines across Canadian Provinces 2014
waterreport08_web BC Govt of Health report titled Progress on the Action Plan for Safe Drinking Water dated 2008

drinking-water-report-2011 Progress on the Action Plan for Safe Drinking Water in BC 2011

Canadian Fracking Lacks Credible Groundwater Monitoring: Expert

Between Environmental Officers being let go and Scientists still working afraid to speak out how are we to know what is happening to our groundwater except for individuals like Jessica Ernst standing up for us to speak out on our behalf. She doesn’t need us, we need her. Click here for the source of the article and stand behind and support Jessica Ernst if you can. Thanks.

 

 

The Alberta Energy Regulator has also reported the contamination of a shallow aquifer by fracking fluids in Grand Prairie in 2012.

Industry, government and media “mantras” of fracking as problem-free industry stem from a near total absence of good science and proper groundwater monitoring across North America, Cherry said.

“I found no cases where rigorous groundwater monitoring has been done at any fracking pad. Exactly zero, not a single one. Anywhere, ever,” Cherry said during his recent Toronto talk.

‘International delinquents’

Cherry also said that dismissive comments by Rich Coleman, British Columbia’s minister of Natural Gas Development, about water concerns and fracking weakened the industry’s social licence.

Last year, Coleman called a Vancouver Province editorial on the water impacts of shale gas fracking by geologist David Hughes and journalist Ben Parfitt as “unfounded and inaccurate.”

Cherry called such comments by a politician irresponsible. “As an expert, I know that British Columbia has invested very little money in the type of research and monitoring that it would need to make statements about shale gas being safe.”

An effective groundwater monitoring system, as first set out by Vancouver engineer Frank Patton in 1998, places measuring devices into specifically-designed wells that sample and track the movement of water contaminants over time and at various depths from a variety of locations. Not even the oilsands has set up such a basic system, said Cherry.

Given that industry spends millions of dollars on the fracking of unconventional deposits and often billions in certain regions, it is imperative that government funds basic research to protect groundwater and the atmosphere, he said.

Asked why government was reluctant to monitor a public resource as valuable as groundwater, the hydrologist replied that it costs money to monitor past societal mistakes. “Groundwater pollution develops slowly over years and decades. If there is anything that government can shrug off to the future, it’s groundwater.” 

 

Cyanobacteria: Algae bloom scuttles Free Fishing Weekend Saturday’s event at Lost Creek Lake was canceled by the Oregon Health Authority; Anabaena flos-aquae algae can be toxic

This is the most comprehensive warning I have read regarding what to do during a bloom. I do not agree with their statement regarding some  “Not all blue-green algae strains produce toxins dangerous to people or pets, and not all blooms release toxins.” I don’t feel they know everything about cyanobacteria to make that statement when there are over 1100 different species and huge gaps within their knowledge base according to Cyanobacteria experts in 2004. Click here for the source or read an excerpt below.

 

June 05, 2014

By Mark Freeman

Mail Tribune

A blue-green algae bloom at Lost Creek Lake may or may not be toxic to people and pets, but it proved fatal to a Free Fishing Weekend event planned there Saturday.

The Oregon Health Authority on Tuesday afternoon issued an advisory against water contact at the lake — the first advisory issued this year in Oregon — after the discovery of a large bloom of cyanobacteria at Jackson County’s largest water body, which prompted Oregon State Parks officials to cancel the annual fishing event.

Water tests showed more than 3.2 million cells per milliliter of Anabaena flos-aquae, a cyanobacteria that has bloomed regularly in late spring at the Rogue River reservoir 30 miles north of Medford, according to the U.S. Army Corps of Engineers, which operates the lake.

Anabaena flos-aquae can produce potentially dangerous toxins, particularly when the bloom dies off. But not all blooms are toxic. The threshold for a public-health advisory in Oregon is 100,000 cells per milliliter.

State parks officials canceled the event Wednesday, but the Oregon Department of Fish and Wildlife still plans to release 5,250 rainbow trout there this week.

During advisories, people and pets are warned to avoid all water contact, but compliance is voluntary. Anglers are encouraged to practice catch-and-release fishing during advisories.

People who eat fish from algae-tainted waters should remove all fat, skin and organs before cooking, because toxins can collect there. People should not eat crayfish or freshwater shellfish taken from infested lakes during an advisory.

Boating and fishing are considered safe so long as boat speeds do not create excessive water spray, according to health officials.

Toxins cannot be filtered by standard camp filters or by boiling the water. In-home filtering systems cannot cleanse the water, though public treatment plants can reduce algae toxins through filtration and disinfection.

Exposure to toxins can produce symptoms of numbness, tingling and dizziness that can lead to difficulty breathing or heart problems, and require immediate medical attention. Symptoms of skin irritation, weakness, diarrhea, nausea, cramps and fainting should also receive medical attention if they persist or worsen.

Children and pets are at increased risk for exposure because of their size and level of activity.

The public will be advised when the concern no longer exists.

Not all blue-green algae strains produce toxins dangerous to people or pets, and not all blooms release toxins.

No confirmed human illnesses have been tied directly to an algae outbreak in Oregon. However, at least four dogs have died in recent years from toxins in water near the Umpqua River near Elkton.

Reach reporter Mark Freeman at 541-776-4470 or mfreeman@mailtribune.com.

Zoonosis: Giardiasis – the facts of infectious disease

I’m trying to find out if birds can spread Giardia (aka Beaver Fever) and after reading multiple websites it does. Most state that birds more likely get the bacteria from humans which is why most state the bacteria is found in pet birds but there are some websites stating it is also found in wild animals. So far this is all I’ve been able to find. So until I find an actual study that provides me with more information I’m going to assume that all birds have the ability to spread this disease. Click here for the full article or read an excerpt below.

 

What is Giardiasis?

Giardiasis is a type of gastroenteritis (gastro) caused by a tiny parasite, Giardia lambia which lives in the bowel.

Giardiasis can affect anyone, however, it is more common in infants, young children and adults aged from 20 to 40 years.

What are the symptoms of Giardiasis?

The most common symptoms of giardiasis are diarrhoea, nausea and stomach cramps. However, in some cases there may be no symptoms at all. After infection, it usually takes between seven and ten days before you become ill. To trace the cause of the illness, it is necessary to know where you were and what you ate and drank in the fortnight before you became ill.

Illness may last from a few days to weeks.

Where are Giardia found?

Giardia lambia parasites are found in humans and in wild, farm and pet animals.

How does Giardiasis spread?

Giardiasis occurs when Giardia parasites are taken in by mouth and the most common way this happens is by person-to-person spread.

People with giardiasis have Giardia lambia parasites in their faeces. If these people do not wash their hands properly after going to the toilet, then contaminated hands can spread the parasites to surfaces and objects which will be touched by other people. Contaminated hands can also spread the parasites to food which may be eaten by other people.

Hands can also become contaminated with parasites when a person changes the nappy of an infant with giardiasis.

People and animals can carry Giardia in the faeces without having any symptoms. These people or animals can still pass the disease on to others.

Pets, farm animals and contaminated drinking water can also spread Giardia parasites.

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I think I may have Giardiasis – what should I do?

If you have symptoms of giardiasis, report them to your doctor immediately. This will ensure that you receive proper treatment and advice and that steps are taken to reduce the spread of the disease.

Can I still work?

Food handlers, child care workers and health care workers with giardiasis must not work until symptoms have stopped.

Children must not attend child care centres, kindergartens or school until symptoms have stopped.

How can I stop spreading it to my family?

In your household the risk of spreading giardiasis can be reduced. It is very important that people with giardiasis or gastroenteritis do not prepare or handle food which will be eaten by other people and that no one shares their towel or face washer.

How can I avoid getting Giardiasis?

By following the guidelines below, everyone can do something to avoid getting giardiasis.

Careful hand washing

Everyone should wash their hands thoroughly with soap and hot running water for at least ten seconds:

• before preparing food
• before eating
• after going to the toilet or changing nappies
• after smoking
• after using a tissue or handkerchief
• after working in the garden
• after playing with pets

Food handlers should use disposable paper towels or an air dryer to dry their hands. Cloth towels are not recommended as they get dirty quickly and can spread germs from one person to another.

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Safe food storage and handling

• Thoroughly cook all raw foods.
• Thoroughly wash raw vegetables before eating.
• Reheat food until the internal temperature of the food reaches at least 75 degrees C.

Note for microwave oven users

Remember that part of the microwave cooking process, includes standing time. If a microwave oven is used, read the manufacturer’s instructions carefully and observe these standing times to ensure the food is completely cooked before it is eaten.

Household cleaning

Bathrooms and toilets must be cleaned often to avoid the spread of infections. Pay particular attention to toilet seats and handles, taps and nappy change tables.

Sandpits can become contaminated with animal faeces and urine. Rake the sand frequently and remove any animal faeces. Cover the area when not in use.

Water from untreated sources

Untreated water that comes directly from lakes or rivers may be contaminated with faeces from people or animals. Boil water from these sources before drinking it.

Child care centres

Children are particularly susceptible to giardiasis. Nappy changing and children’s lack of proper hygiene makes the transmission of this disease in child care settings particularly high. It is important that thorough hand washing and cleaning procedures are being followed in the child care centre to control the spread of these parasites.

 

 

How do I clean rust on baking pans?

Click here for the tip from Rachael Ray.

 

Dear Cleaning Lady:

I have had my trusty 9 x 13 brownie pan forever and I am noticing some rust spots. Is this dangerous? Can I clean off the rust or should I toss it?

Thanks!

Brownie Baker

Dear BB:

Don’t toss the pan but definitely get rid of the rust before you bake with it again. Here’s how:

1. Rinse the pan and shake it dry – do not wipe with a towel because you want it to be slightly damp.

2. Dust it lightly with baking soda (it should stick because of the remaining water), making sure you cover the spots that are rusting.

3. Leave the dusted pans for about half an hour.

4. Clean the pan gently with a scourer making sure you get rid of all the rust leaving just the exposed metal underneath.

5. Rinse the pan to get rid of all the baking soda and towel dry it.

6. To make sure your pan doesn’t rust again coat it with cooking oil.

Tips:

• The pans build up a layer of oil, so don’t panic if there is some residue.
• Follow the steps above once or twice a year to avoid rust.
• Skip the dishwasher if you want to avoid rust and just clean the pans lightly after use.

 

Drinking Water Contaminants

A quick summary of the medical problems someone can get if they drink contaminated water for a long time. Click here to learn more.

Cyanotoxins: Potential Impact of Cyanobacteria on Crop Plants

This is really scarry and I’m not sure how to protect oneself from ingesting toxins especially when we buy our food from the store because it could be in packaged goods. Perhaps the answer is to grow our own food so at least we know how it is grown and watered. Toxins could cause acute poisoning or become carcinogenic through chronic exposure. Click here to read the entire article or an excerpt below. 

…

Is Human Health at Risk when Growing or Consuming Crops in Oregon?

Any direct contact between contaminated waters and the human body exposes one to toxic effects. Overhead irrigation of crops with water containing cyanotoxins poses an inhalation risk to field workers. Exposure symptoms include rashes, asthma and dry sporadic cough with vomiting on the days of, and after, exposure.2 Exposure in rare cases can cause death.

Much less is known about human health risks through the consumption of plant products exposed to cyanotoxins. Currently there are no regulatory limits for microcystin loads in plant tissue but there are recommendations set by the World Health Organization. Six-day-old plants of green pea, sugar pea, chickpea, green and red mung bean, snap bean, soybean, alfalfa, lentil, wheat and corn were exposed to either purified microcystin or cyanobacterial laden lake water.8 All of these crops were found to accumulate toxin and peroxides in shoots and roots to high enough levels that consumption of a small amount of plant tissue would exceed recommendations set by the World Health Organization (Table 1). In another study, water containing cyanobacteria was applied to the shoots of four different crops. The contaminated water ran off of rape and ryegrass, where absorption of microcystin was not observed, while lettuce and clover retained microcystin.4 Though there is currently limited evidence, it appears that when certain crops are exposed to environmentally realistic concentrations of microcystin-LR, this toxin can accumulate to levels where even a small serving of plant product (0.7 to 9 oz) would exceed the World Health Organization recommended consumption limit. This consumption limit is based on acute poisoning3 and does not consider the potential of microcystin as a carcinogen through chronic exposures.5

…

New Zealand: CYANOBACTERIAL WARNING UPDATE: Health warning for Lake Whangape

Here is another warning from New Zealand. I like the bolded section below. Click here to read the entire warning.

Waikato DHB
Tuesday 03 December 2013, 10:52AM
Media release from Waikato DHB

A new health warning has been issued today for Lake Whangape, north of Huntly. The lake has had a rise in the number of cyanobacteria cells and a rise in biovolume since last tested one month ago.

Both Lake Waikare and Lake Ngaroto continue to have a cyanobacterial health warning in force.

Waahi, Hakanoa, and Rotoroa (Hamilton Lake), the other lakes that are tested regularly, all currently remain below the warning level for cyanobacteria, despite a rising trend.

Cyanobacteria are a form of algae which can produce toxins harmful to the health of humans and animals exposed to, or swallowing the water where the algae are growing.

Testing is carried out by Waikato Regional Council monthly during the warmer months, and two monthly over the winter. The lakes which are tested may indicate, to some extent, cyanobacterial levels in other shallow lakes in the region.

“During blooms, lakes should not be used for any activity that involves skin contact with the affected water. Swallowing water from lakes affected by blooms should also be avoided,” said medical officer of health Dr Richard Wall.

“Scums are a particular risk because they contain a high level of toxins. If contact with scum does occur, skin should be rinsed clean and clothing changed as soon as possible. This warning is particularly important for children.

“If people still choose to use the lakes when warnings are in place, or any other lake where there are visible changes to water colour, they should shower and change their clothing as soon as possible afterwards, even if no symptoms are noticeable.”

Symptoms include rash, skin and eye irritation; allergy symptoms such as hayfever and asthma; and possibly stomach upsets including diarrhoea and vomiting.

These symptoms may not appear until some time after contact with the affected water. Long-term exposure to cyanobacterial toxins may cause additional health risks.

Waikato Regional Council no longer routinely tests Lake Kainui; however, caution is still advised for users of this lake because of its history of cyanobacterial blooms.

Test results should be used for general guidance only, as cyanobacteria and their toxins are not evenly spread through any lake and may be concentrated in some areas by wind and water movements. Cyanobacterial blooms can happen very quickly when conditions for growth are favourable.

The Waikato DHB Population Health service would like to be informed about health problems that develop after exposure to any of the Waikato lakes. Health advice is also available from the Population Health on (07) 839 8899 in and out of hours.

Up-to-date information on cyanobacterial cell counts is available from local councils and Waikato Regional Council.