CCA - Copper Chrome Arsenic, a mouthful you could never digest.

Treated timber in playspaces, CCA, ACQ, LOSP & Tanalith E.

This summary is an excerpt from  my book "Garden maintenance for playspaces" and is referenced through the Information derived from the CSIRO, APVMA, ERMA, EnHealth, US EPA, Better Health Victoria 

                                                                                                              

Summary
Be aware of the regulations/ legislation in place in your country in respect to the use of timber treated with CCA preservatives. In Canada, the US and Europe their use is prohibited, in others the use of existing structures is allowed (using recommended procedures- see below), in some no guidelines exist.

1) There are no conclusive studies that link playground structures made with timber treated with CCA and cancer. In fact there are a number of studies focused on children’s play environments that indicate that any transfer of arsenic in any form did not pose a health risk.[i] [ii] The UK Health and Safety Executive released the following directive,”Play providers and users should be assured that there is no need to remove CCA-treated items that are otherwise in good order simply because of the presence of CCA. The risk from CCA in this case is extremely low”[iii]

2) A link between handling CCA-treated timber (using recommended procedures) and cancer has not been demonstrated, as the potential ingestion rates of arsenic that can be calculated from valid available research are well within tolerable limits[iv].

3) For the wary the following precautions are advised:
· Always wash your hands before eating,
· Do not use wood chip (fines) mulch that have originated from CCA treated timber,
· Paint any existing structures made from CCA timber with exterior coloured UV (opaque) paint. Structures that are constantly used will obviously show greater wear, repaint them yearly or as required.
· If you have or intend to use CCA treated timber in the construction of a raised garden bed line the inside of the bed with plastic and/or plant any root crops at least 100mm from the wood.
· Do not clean CCA treated timber with bleaches, deck cleaners or brighteners that contain sodium hypochlorite, sodium hydroxide, sodium percarbonate, oxalic acid, or citric acid may release toxic chemicals from CCA-treated wood.
· If any construction is being carried out on existing CCA structures ensure that cuts are sealed as above and that any off cuts are disposed off as per your localities regulations. Any individual carrying out work on the structures should be familiar with the PPE that is required as well as safe work procedures relating to any dust generated, sealing of cuts and disposal of off cuts. Under no circumstances can the off cuts be disposed of by burning

4) If, despite the information provided here you are still unhappy or wary of the use of CCA treated timber or have or know of a child who has a particular sensitivity to CCA treated timber DO NOT USE IT, use ACQ, LOSP or Tanalith E- where available).

The main concern with CCA is that it contains arsenic. While not a mutagen, arsenic acts as a carcinogen when ingested at rates above certain tolerable limits. It may initiate skin and liver cancers. The safe or tolerable amounts of arsenic that can be ingested by humans have been accurately determined because, unlike most other pesticides, arsenic occurs naturally and can be found in relatively high levels in the drinking water of some towns in Bangladesh, Japan, Argentina and Taiwan.

Extensive research has shown that arsenic is safe or tolerable to ingest at rates below two µg/kg of body weight per day (World Health Organisation limit), or three µg/kg of body weight per day (Food Standards Australia limit).

Arsenic is the 20th most common element on earth, so the ability for animal life to cope with some level of arsenic is to be expected. Arsenic occurs naturally in Australian soil at concentrations between 0.2 and 50 parts per million (ppm, equal to mg/kg), with an average of five to six ppm.

Copper chromium arsenic (CCA) is Australia's most widely used wood preservative. It has been used safely in Australia for 50 years and some 120 treatment plants are currently operating around the country. During CCA treatment, timber is impregnated with the preservative solution using controlled vacuum/pressure processes

The arsenic used in CCA is in a form (arsenate or pentavalent arsenic) that is five to ten times less toxic than the most toxic form, arsenite (trivalent arsenic). Fixation modifies the arsenate into metal-metal complexes and organo-complexes with wood. Ingestion studies with animals have shown that this greatly reduces its mammalian toxicity.

The fixation process ensures that virtually all the CCA becomes chemically bonded within the wood structure. Since March 2006 producers have been obliged to ensure that the product is adequately fixed before dispatching it from their sites.

The majority of the CCA fixed within timber remains there over its lifetime of service. If it did not, the wood would rot and fail in much less than the 30 - 50 year period for which it is often guaranteed. However, a small amount of leaching inevitably occurs. This can show up in small rises in arsenic levels in the soil close to posts and poles. Studies have found levels return to normal within about 100 mm of posts and 150 - 200 mm of poles or decking.

A number of studies have shown that CCA is not absorbed into above-ground food crops such as grapes[v], tomatoes and cucumbers. There are, however, some reports of a slight increase in arsenic content in root crops such as carrots and beets grown against treated timber, although the arsenic is in a safe organic form and most of it is removed with peeling. Any concern can be eliminated by growing these vegetables more than 100 mm from treated timber garden edgings or by lining the edgings with plastic.

Painting sawn CCA-treated timber has long been recommended as a way of reducing warping and checking and will also reduce dislodgeable arsenic from the timber surface. Oils, stains and clear finishes are often not particularly durable coatings, so that arsenic may still dislodge from the coated timbers. The more durable exterior coloured (opaque) paints reduce levels of dislodgeable arsenic more significantly [vi] [vii].

In Australia, CCA preservatives are regulated by the Australian Pesticides and Veterinary Medicines Authority (APVMA). The APVMA implemented a number of restrictions on CCA that became effective in March 2006. The main implementation affecting the public is that CCA is no longer used to treat timber for structures where there is frequent and intimate contact, such as playground equipment, picnic tables, handrails, decking boards, garden furniture and exterior seating.

A review by ERMA in New Zealand[viii] did not find increased health risks from using CCA-treated timber. Nevertheless, the APVMA felt that more studies were needed to support the continued use of a potential carcinogen in high human contact applications and that without those studies it should be restricted.

An important question, following the APVMA decision to restrict CCA for certain uses, is whether to retain existing CCA-treated timber structures, especially playgrounds. Ultimately, this will be an individual's or organisation's decision. Credible research to date suggests that arsenic ingestion from handling CCA-treated timber occurs at well below tolerable levels if the precautions mentioned above are followed.

You therefore need to make your own informed decisions, and not necessarily believe alarmist claims. Note that the USA EPA in its announcement to restrict CCA stated: 'EPA has not concluded that CCA-treated wood poses unreasonable risks to the public for existing CCA-treated wood being used around or near their homes or from wood that remains available in stores. EPA does not believe there is any reason to remove or replace CCA-treated structures, including decks or playground equipment. EPA is not recommending that existing structures or surrounding soils be removed or replaced.'

Similar statements in Australia can be found from EnHealth Council[ix] and Better Health Victoria[x].

One study by the CSIRO in some local kindergartens found that playground equipment would not pose a health risk due to arsenic[xi]. This suggestion was further supported by a comprehensive study in Canada of dislodgeable arsenic levels on the hands of children, which were lower than anticipated in the APVMA review[xii].

ACQ - Alkaline Copper Quartenary is a relatively new treatment which is a water based solution (copper, Didecyldimethylammonium chloride and water) which uses copper to protect against rot and fungal attack and Ammonium Quartenary as a pesticide. ACQ treated timber possesses most of the same qualities as CCA timber in that it can be used in inground applications. It is considered a very safe and very effective product with no risk to humans. At the moment it is approximately 25% more expensive than the CCA and can be sometimes difficult to source. The Osmose company produces both ACQ and LOSP sealants[xiii] .

LOSP - Light Organic Solvent Preservative is a treatment that is usually a white spirit based solvent which contains copper naphthenates and synthetic pyrethroids as well as other chemicals to provide protection from insects and decay. As an alternative to CCA and ACQ treated timber it is generally more expensive and far less effective.

LOSP treated pine is usually machined to the required lengths and shapes before the treatment is applied. As a result of this less pressure is used in the treatment process and a little less penetration of solution is achieved. This does not affect the longevity of the timber, however it means that LOSP timber must not go in ground and if the timber is cut the cut ends must be resealed with a suitable sealant. Most LOSP treated pine must be painted to maintain its warranty, without painting LOSP treated timbers may only last a few years. NB: The exact type of LOSP treatment will determine its lifespan, and if it has to be over painted. Always request from your supplier written details of painting requirements for any LOSP products. Additionally, due to the solvents in LOSP products they are generally more flammable.

LOSP timber is frequently coated with a protective oil based primer which is usually pink. This primer is applied to stabilise and protect timber during storage and installation, not as a paint primer. As a result it is recommended that LOSP primed timber be sanded down to remove the primer before painting. Unprimed LOSP timber is natural in its appearance as the solution used is clear and hence causes no discolouration of the timber. Like CCA the timber will weather and discolour if not stained or painted.

Tanalith E or Copper Azole - is a new water borne solution which again uses copper as a fungicide and azole as a pesticide, it can be used in inground applications and has most of the same properties as CCA treated timber. Water-based preservatives like copper azole leave wood with a clean, paintable surface after they dry. There are two types of Copper Azole: A (CBA-A), and B (CA-B). Copper azole wood preservative is used for treating a variety of softwood species including southern pine, red pine, ponderosa pine, hem-fir and Douglas fir.

· CBA-A: Copper Boron Azole type A was standardized by the American Wood-Preservers' Association (AWPA)1 in 1995 and contains the following ingredients: copper (49%), boron as boric acid (49%), and azole as tebuconazole (2%). Wood treated with CBA-A has a greenish-brown colour and little or no odour.

The use of CBA-A has been generally supplanted by the newer CA-B product.
· CA-B: Copper Azole type B was standardized by the AWPA in 2002 and is composed of copper (96.1%) and azole as tebuconazole (3.9%). Wood treated with CA-B has a greenish-brown colour and little or no odour. CA-B is in widespread use throughout the United States and Canada.

Koppers[xiv] produce a product called Tanalised Ecowood which meets US EPA and European Union standards for use in playgrounds.


[i] Cookson LJ. 2005. Arsenic content of soil and wood chip fines in three kindergartens Ensis Technical Report No. 151, 16 pp.
[ii] Kwon E, Zhang H, Wang Z, Jhangri G, La X, Fok N, Gabos S, Li XF, Le X. 2004. Arsenic on the hands of children after playing in playgrounds. Environmental Health Perspectives 112: 1375-1380.
[iii] UK H&SE Guidance: Copper, Chrome and Arsenic Treated Timber in Children's Playgrounds. Local Authority Circular 47/18, 2004.
[iv] http://www.csiro.au/resources/CCATreatedTimber.html
[v] Levi MP, Huisingh D, Nesbit WB. 1974. Uptake by grape plants of preservatives from pressure-treated posts not detected. Forest Products J. 24: 97-98.
[vi] Lebow S, Foster D, Lebow P. 2004. Rate of CCA leaching from commercially treated decking. Forest Products J. 54: 81-88.
[vii] Stilwell DE and Musante CL. 2004. Effect of Coatings on CCA Leaching From Wood in a Soil Environment. In: pre-conference proceedings, Environmental impacts of preservative-treated wood. Florida Center for Solid and Hazardous Waste Management, Gainesville, Florida, pp 113-123.
[viii] Read D. 2003. Report on Copper Chromium and Arsenic(CCA) Treated Timber Environmental Risk Management Authority (ERMA).
[ix] EnHealth. 2005. enHealth Council position on copper chrome arsenate (CCA) treated timber products
[x] Better Health. 2005. Copper chrome arsenic (CCA) treated timber
[xi] Cookson LJ. 2005. Arsenic content of soil and wood chip fines in three kindergartens
[xii] Kwon E, Zhang H, Wang Z, Jhangri G, La X, Fok N, Gabos S, Li XF, Le X. 2004. Arsenic on the hands of children after playing in playgrounds. Environmental Health Perspectives 112: 1375-1380
[xiii] http://www.osmose.com.au/
[xiv] http://www.koppers.com.au/ArticleDocuments/38/Tan%20E%20FAQ_2.pdf.aspx?Embed=Y

The unholy trio of the sandpit - Toxoplasmosis, Meliodosis and Silicosis Pt 3

The summaries I will present in the next few posts are excerpts from  my book "Garden maintenance for playspaces" and are referenced through the Centre for Disease Control (CDC), USGS, International Agency for Research on Cancer (IARC), The Children's Environmental Health Center, Mount Sinai School of Medicine. New York, Occupational Safety and Health Administration  (OSHA), OEHHA’s (Office of Environmental Health HazardAssessment) & the Northern Territory State government

Part 3 - Silicosis
Summary 

1) Sand is a naturally occurring granular material composed of finely divided rock and mineral particles. The composition of sand is highly variable, depending on the local rock sources and conditions but the most common constituent of sand in inland continental settings and non-tropical coastal settings is silica .The composition of sand is highly variable, depending on the local rock sources and conditions...’ 

2) Silicosis is a form of occupational lung disease caused by inhalation of crystalline silica dust. While crystalline silica is a known human carcinogen, the amount of exposure is a factor.

3) During the 1980’s studies by the International Agency for Research on Cancer (IARC) determined that continued exposure to certain concentrations of crystalline silica dust over extended periods without the use of PPE or work safety practices caused it to act as a carcinogen. The silica was usually fine dust specially formulated for industries (i.e. sand blasting, glass foundries etc.), or was a component of bulk lots used in other industries.

4) Rather than assess each of the 650,000 produces containing crystalline silica dust the US Occupational Safety and Health Administration (OSHA) released a generic Hazard Communication Standard (HCS). Under the HCS, OSHA regulated that businesses that use materials containing 0.1% or more crystalline silica must follow Federal guidelines concerning hazard communication. Specifically, HCS has the following requirements: Chemical manufacturers and importers—must determine the hazards of their products.

5) In 1986 the State of California passed Proposition 65. Like the OSHA’s HCS, Proposition 65 put the burden of proof on business instead of government to make a key scientific determination about safety levels for specific chemicals. Under Prop. 65 any product that may contain any substance may be hazardous has to be labelled with the generic warning “WARNING: This product contains chemicals known to the State of California to cause cancer and birth defects or other reproductive harm.”[i]

6) Because of the OSHA & OEHHA’s onus on suppliers and distributers providing proof of their product being safe most simply choose to supply the generic warning[ii] [iii] if their product contains any of the chemicals contained in the OEHHA’s list[iv].

7) There are a number of sand types available to consumers to use in sand play pits/boxes. “Safe” play sand suppliers suggest that their sand (beach or river sand) is better for childrens play as it has been washed, screened and graded They state that most bagged sand is obtained from crushed quarry quartz which, may/may not also contain tremolite. Some scientists believe tremolite particles can cause cancer like other forms of asbestos to which humans are exposed.

8) There are very few long term studies that can provide a definitive answer as to whether children playing in sand may be exposed to carcinogenic substances (with so many variables i.e., what types of sand is it, were was it obtained, what is its composition, what are the concentrations of its components, what type of environment is the sand pit box in, how long is the child at play, etc.) One researcher, Dr. Michael Babich, a scientist at the Consumer Product Safety Commission who worked on a study that looked specifically at play sand and children's exposure to it suggests, ‘Researchers would have to follow children for a lifetime, and even then couldn't distinguish cancers from a crystalline silica exposure and those from other environmental exposures, like pollution.’

9) Simple safety protocols for sand play would be: 
· Make sure that the sandboxes children come in contact with in all early childhood settings are outdoors. 
· Keep sandboxes damp (not necessarily wet), to keep any dust down. This step is especially important in arid climates. 
· Be aware as to the source of the play sand you intend to use. Do not use bagged play sand that has been derived from crushed quarry quartz. Purchase River or Beach sand that has been washed and screened/graded. 
---------------------------------------------------------------------------------------------------------
Silicosis, also known as Potter's rot, is a form of occupational lung disease caused by inhalation of crystalline silica dust, and is marked by inflammation and scarring in forms of nodular lesions in the upper lobes of the lungs. Silica occurs in 3 forms: crystalline, microcrystalline (or cryptocrystalline) and amorphous (non-crystalline). 

Silicosis is due to deposition of fine respirable dust (less than 10 micrometers in diameter) containing crystalline silicon dioxide. While crystalline silica is a known human carcinogen, the amount of exposure is a factor. Chronic simple silicosis usually results from long-term exposure, 10 years or more, to high concentrations of respirable silica dust. Accelerated silicosis usually occurs after 5–10 years of exposure to higher concentrations of silica dust. Acute silicosis is known to develop after few weeks to 5 years of exposure to high concentrations of respirable silica dust. [v] 

During the 1980’s studies were performed by the International Agency for Research on Cancer (IARC) in industries where workers were continually exposed to high concentrations of respirable crystalline silica (i.e. stone masons, quarrymen, miners, sandblasters, ceramicists, potters, foundry workers, grinders, stone cutters, brick workers etc.) The studies determined that crystalline silica was a carcinogen. As a result of these findings, crystalline silica was regulated under the Occupational Safety and Health Administration's (OSHA) Hazard Communication Standard (HCS). Under the HCS, OSHA regulated that businesses that use materials containing 0.1% or more crystalline silica must follow Federal guidelines concerning hazard communication. 

In the development of the HCS, OSHA realized that the task before it was herculean: to evaluate all the substances to which workers are exposed, as many as 650,000 of which were potentially hazardous. The Agency decided to adopt a generic approach, and promulgated the HCS, which requires container labelling, material safety data sheets, and training. Specifically, HCS has the following requirements: Chemical manufacturers and importers—must determine the hazards of the product. Suppliers are held responsible for determining whether a substance is covered, including whether the quantity of the hazardous chemical in a mixture exceeds these cut-offs. Testing is not required; the employer may assume that if the hazardous chemical is present, the mixture is covered.” [vi] 

In 1986 the State of California passed Proposition 65 (formally titled "The Safe Drinking Water and Toxic Enforcement Act of 1986. Its goals were to protect drinking water sources from toxic substances that cause cancer and birth defects and to reduce or eliminate exposures to those chemicals generally by requiring warnings in advance of those exposures. Like the OSHA’s HCS, Proposition 65 put the burden of proof on business instead of government to make a key scientific determination about safety levels for specific chemicals. 

In addition because the law allowed private citizens to sue and collect damages from any business violating the legislation there have been cases of lawyers and law firms using Proposition 65 to force monetary settlements out of California businesses.[vii] The Californian Attorney General's office has cited several instances of settlements where plaintiff attorneys received significant awards without providing any environmental benefit. 

Under Prop. 65 any product that may contain any substance that may be hazardous has to be labelled with the generic warning “WARNING: This product contains chemicals known to the State of California to cause cancer and birth defects or other reproductive harm.”[viii] 

Because of the OSHA &the OEHHA’s (Office of Environmental Health Hazard Assessment) onus on suppliers and distributers providing proof of their product being safe, most simply chose to supply the generic warning[ix] [x]if their product contains any of the chemicals contained in the OEHHA’s list.[xi] 

The OEHHA’s own website recognises in its FAQ’s that the warning may mean something or... ..nothing. 

“Q: I recently bought a product that came with a Proposition 65 warning. How do I find out more about the warning and the chemicals in the product? 

A: Businesses are not required to provide OEHHA with any information regarding their Proposition 65 warnings. ....A business is not required to notify our office or any other regulatory agency when it decides to provide a warning. 

Q: Is a product safe if it carries a Proposition 65 warning? 

A: The fact that a product bears a Proposition 65 warning does not mean by itself that the product is unsafe. You could think of Proposition 65 more as a “right to know” law than a pure product safety law. 

Q. What is the acceptable concentration in my product for chemicals listed under Proposition 65? 

A. Under Proposition 65, there are no acceptable concentrations established for any listed chemical in any given product. An exposure that causes a significant risk of harm from a listed chemical through the use of a product would trigger the warning requirement, not merely the fact that a listed chemical is present in a product. The concentration of a listed chemical would certainly factor into the level of exposure that would result from an individual using a given product. But concentration alone is not sufficient to determine if warnings are required. 

Nola Enge a doctoral student at the Arizona State University in her article Is your child's sandbox a safe place to play? provides information derived from Dr. Michael Babich, a scientist at the Consumer Product Safety Commission (CPSC). ’I turned to Dr. Michael Babich, a scientist at the Consumer Product Safety Commission who worked on the one study I found that looked specifically at play sand and children's exposure to it (CPSC, 2004, p. 71). While this study has not reached any definitive conclusions yet, he was able to help me understand the following: 

The science is not well understood with regard to childhood exposure because there is no way to get the answers. Researchers would have to follow children for a lifetime, and even then couldn't distinguish cancers from a crystalline silica exposure and those from other environmental exposures, like pollution. 

It is much easier to show a connection between cancer and workers in high-risk occupations. They are exposed to higher levels for longer periods of time than children are in the sandbox. 

The CPSC study measured many different brands of play sand and found most of their samples were between 90-100 percent pure crystalline silica. Although children are exposed to crystalline silica in the sandbox, we just don't know at what levels or how it affects them. Babich said that we do know the risk to children is, at worst, much lower than it is for workers. Children are exposed at lower levels and intermittently’ (M. Babich, personal communication, August 26, 2005). 

Enge suggests that a prudent safety protocol would be to: 

· Make sure that the sandboxes children come in contact with in all early childhood settings are outdoors. 
· Keep sandboxes damp (not necessarily wet), to keep the dust down. This step is especially important in arid climates. 
· Purchase play sand, not all-purpose sand. Generally, play sand is grainier because it has been washed and screened, so the really fine dust is washed away. 

A fairly absolute clarification of the topic can be found in the attached personal correspondence from Dr Philip J. Landrigan, MD, MSc, Professor of Pediatrics, Director, Children's Environmental Health Center, Mount Sinai School of Medicine. New York, 4th September 2011. 

“Dear Mr Reed 

Thank you for your email. 

Silicosis is not a risk for children in sand boxes. Silicosis is an industrial lung disease of workers who are occupationally exposed for many years to very high levels of airborne silica such as sandblasters and quarry workers. There is no way that children, even with their delicate lungs and airways, can attain levels of exposure in a sandbox that are anywhere close to those required to induce silicosis. 

With regard to exposure to asbestos-like minerals in play sand, the situation is very different. The issue is that some play sand is not beach sand (which is what I had always imagined), but instead is produced by crushing quarried rock that has been mined in quarries where the native rock contains asbestos. When this rock is crushed to make play sand, the asbestos – which is a fibrous mineral - is released. These asbestos fibers are microscopic in size and can be inhaled by children if the sand is tossed into the air during play or lifted by the wind. I can attest that these fibers are present in some samples of commercially purchased play sand, because I have seen images of these fibers that my team took through the electron microscope. 

Unlike silica, even very small exposures to inhaled airborne asbestos are dangerous for children because the inhaled asbestos fibers can lodge in the lung tissue where they are virtually indestructible, cause chronic irritation/inflammation of the lining of the lungs, the pleura, and decades later cause a cancer named human malignant mesothelioma, a very nasty tumor, almost universally fatal, that typically kills within one year of diagnosis. 

This was the basis for my statement that "If children inhale these fibers they are at risk of getting lung cancer later,'' he said. ''Either this play sand should be banned or labeled with a skull and crossbones.'' ' 

Hope this helps 

Philip J. Landrigan, MD, MSc 

Dean for Global Health 
Ethel H. Wise Professor and Chairman 
Department of Preventive Medicine 
Professor of Pediatrics 
Director, Children's Environmental Health Center 
Mount Sinai School of Medicine 
17 East 102nd Street, Room D3-145 
New York, NY 10029-6574 
WHO Collaborating Centre in Children’s Environmental Health 

[i] http://oehha.ca.gov/prop65.html 
[ii] http://www.prop65news.com/pubs/brochure/madesimple.html 
[iii] http://en.wikipedia.org/wiki/California_Proposition_65_(1986)#cite_note-House-13 
[iv] http://www.oehha.ca.gov/prop65/prop65_list/files/P65single072911.pdf 
[v] http://en.wikipedia.org/wiki/Silicosis 
[vi] Crystalline Silica Primer, US Dept of the Interior and US Bureau of Mines, 1992 
[vii] http://ag.ca.gov/newsalerts/release.php?id=1207 
[viii] http://oehha.ca.gov/prop65.html 
[ix] http://www.prop65news.com/pubs/brochure/madesimple.html 
[x] http://en.wikipedia.org/wiki/California_Proposition_65_(1986)#cite_note-House-13 
[xi] http://www.oehha.ca.gov/prop65/prop65_list/files/P65single072911.pdf

The unholy trio of the sandpit - Toxoplasmosis, Meliodosis and Silicosis Pt 2

The summaries I will present in the next few posts are excerpts from my book "Garden maintenance for playspaces" and are referenced through the Centre for Disease Control (CDC), USGS, International Agency for Research on Cancer (IARC), The Children's Environmental Health Center, Mount Sinai School of Medicine. New York, Occupational Safety and Health Administration (OSHA), OEHHA’s (Office of Environmental Health HazardAssessment) & the Northern Territory State government


Part 2 - Melioidosis
Summary
1) Melioidosis, also called Whitmore's disease, and is caused by the bacterium Burkholderia pseudomallei.
2) It can infect humans and animals.
3) It is predominately a disease of tropical climates, especially in Southeast Asia and northern Australia. The bacteria causing melioidosis are found in contaminated water and soil. It is spread through direct contact with the contaminated source.
4) Melioidosis infection can be treated with the use of appropriate medication.
5) In those geographic areas mentioned, childcare services can minimised the risk of Meliodosis by:
· Ensuring that your sandpit/digging patch drains well after rain, has a cover that allows evaporation, that the sand/soil is turned over after rain to encourage drying (UV radiation will kill or a sanitising agent- see below)
· Check that any sores/cuts on children are covered with waterproof dressings,
· Ensuring all children wear waterproof shoes when playing outdoors,
· Children should avoid playing in muddy areas, wet sandpits or places where water has pooled in grassy areas or where grassed areas are boggy (*note point 2 above, this is only relevant for those climates that support the bacteria).
· Playing on wet grass is considered to be low risk for acquiring melioidosis. Sandpits which are dry or dry enough to comfortably play in are also low risk[i].

Transmission
Humans and animals are believed to acquire the infection by inhalation of contaminated dust or water droplets, ingestion of contaminated water, and contact with contaminated soil, especially through skin abrasions. It is very rare for people to get the disease from another person. While a few cases have been documented, contaminated soil and surface water remain the primary way in which people become infected.

Signs and Symptoms
There are several types of melioidosis infection, each with their own set of symptoms. However, it is important to note that melioidosis has a wide range of signs and symptoms that can be mistaken for other diseases such as tuberculosis or more common forms of pneumonia.
· Acute Localized Infection: Fever, General Muscle Aches
· Pulmonary Infection: High fever, Headache, Anorexia, General muscle soreness, Chest pain, Cough,
· Acute Bloodstream Infection: Fever, Headache, Respiratory distress, Abdominal discomfort, Joint pain, Muscle tenderness, Disorientation
· Disseminated Infection: Fever, Weight loss, Stomach or chest pain, Muscle or joint pain, Headache, Seizures

The time between an exposure to the bacteria that causes the disease the emergence of symptoms is not clearly defined, but may range from one day to many years; generally symptoms appear two to four weeks after exposure. Although healthy people may get melioidosis, the major risk factors are Diabetes, Liver disease, Renal disease, Thalassemia, Cancer or another immune-suppressing condition not related to HIV.

Risk of Exposure
While melioidosis infection has taken place all over the world, Southeast Asia and northern Australia are the areas in which it is primarily found. In the United States, confirmed cases reported in previous years have ranged from zero to five and have occurred among travellers and immigrants coming from places where the disease is widespread.

The greatest numbers of melioidosis cases are reported in Thailand, Malaysia, Singapore, and Northern Australia. In addition, it is now believed to be widespread in Papua New Guinea, Most of the Indian subcontinent, Southern China, Hong Kong, Taiwan. Though rarely reported, cases are thought to frequently occur in Vietnam, Indonesia, Cambodia, Laos, Myanmar (Burma). Outside of Southeast Asia and Australia, cases have been reported in The South Pacific (New Caledonia), Sri Lanka, Mexico, El Salvador, Panama, Ecuador, Peru, Guyana, Puerto Rico, Martinique, Guadeloupe, Brazil, Parts of Africa and the Middle East,

Treatment
When a melioidosis infection is diagnosed, the disease can be treated with the use of appropriate medication.
The type of infection and the course of treatment will impact long-term outcome. Treatment generally starts with intravenous (within a vein) antimicrobial therapy for 10-14 days, followed by 3-6 months of oral antimicrobial therapy.

In tropical environments melioidosis bacteria live deep in the soil during the “Dry”, but are found in surface water and mud after heavy rainfall in the “Wet”. In addition, there is no vaccine to protect against melioidosis. For these reasons and others, preventing exposure can be difficult. However, there are things that can be done to help minimize the risk of exposure:
· Ensuring that your sandpit/digging patch drains well during after rain, has a cover that allows evaporation, that the sand/soil is turned over after rain to encourage drying (UV radiation will kill or a sanitising agent)
· Check that any sores/cuts on children are covered with waterproof dressings,
· Ensuring all children wear waterproof shoes when playing outdoors
· Children should avoid playing in muddy areas, wet sandpits or places where water has pooled in grassy areas or where grassed areas are boggy.
· Playing on wet grass is considered to be low risk for acquiring melioidosis. Sandpits which are dry or dry enough to comfortably play in are also low risk[ii].

Disinfection
Disinfecting playspace sandpits and digging patches can be completed with the use of numerous disinfectants including benzalkonium chloride, iodine, potassium permanganate, 1% sodium hypochlorite[iii]. Melioidosis is effectively killed by the commercial disinfectants such as Perasafe®[iv]. The microorganism can also be destroyed by heating to above 74°C for 10 min or by UV irradiation. Melioidosis is not reliably disinfected by chlorine[v].

[i] http://www.healthylivingnt.org.au/content/?action=getfile&id=705
[ii] http://www.healthylivingnt.org.au/content/?action=getfile&id=705
[iii] Miller, WR; Pannell, L; Cravitz, L; Tanner, WA; Ingalls, MS (1948). "Studies on certain biological characteristics of Malleomyces mallei and Malleomyces pseudomallei: I. Morphology, cultivation, viability, and isolation from contaminated specimens"
[iv] Wuthiekanun V, Wongsuwan G, Pangmee S, Teerawattanasook N, Day NP, Peacock SJ (2010). "Perasafe, Virkon and bleach are bactericidal for Burkholderia pseudomallei, a select agent and the cause of melioidosis".
[v] Howard K, Inglis TJJ (2003). "The effect of free chlorine on Burkholderia pseudomallei in potable water". Howard K, Inglis TJJ (2005). "Disinfection of Burkholderia pseudomallei in potable water"

The unholy trio of the sandpit - Toxoplasmosis, Meliodosis and Silicosis

Sandpits and digging patches are a constant source of misinformation and over-hyped paranoia. In the past years I have been asked about the risks of toxoplasmosis and melioidosis and silicosis. I have heard numerous complaints about how children playing in pits and patches get “dirty”???, how difficult it is to place a sand pit cover on a sandpit, and my personal favourite, that the sand found in sandpits is carcinogenic.

The summaries I will present in the next few posts are excerpts from  my book "Garden maintenance for playspaces" and are referenced through the Centre for Disease Control (CDC), USGS, International Agency for Research on Cancer (IARC), The Children's Environmental Health Center, Mount Sinai School of Medicine. New York, Occupational Safety and Health Administration  (OSHA), OEHHA’s (Office of Environmental Health HazardAssessment) & the Northern Territory State government 

Part 1 - Toxoplasmosis
Summary
1) Toxoplasmosis is caused by exposure/ingestion of undercooked, contaminated meat (humans and animals).   Cats who are fed undercooked, contaminated meat may carry the parasite in their system.

2) Humans may accidentally swallow the parasite through contact with cat faeces by touching or ingesting anything that has come into contact with cat faeces that contain Toxoplasma (e.g., not washing hands after gardening/play or eating soil/sand that have come in contact with the parasite)

3) Cats who have been fed only canned or dried commercial food or well-cooked table food are not susceptible to contracting and spreading the parasite. Cats only carry Toxoplasma in their faeces for a few weeks following infection with the parasite. The infection will go away on its own.

4) “While the parasite is found throughout the world, more than 60 million people in the United States may be infected with the Toxoplasma parasite. Of those who are infected, very few have symptoms because a healthy person's immune system usually keeps the parasite from causing illness. However, pregnant women and individuals who have compromised immune systems should be cautious; for them, a Toxoplasma infection could cause serious health problems. 

A Toxoplasma infection occurs by: 

· Eating undercooked, contaminated meat (especially pork, lamb, and venison)

· Accidental ingestion of undercooked, contaminated meat after handling it and not washing hands thoroughly (Toxoplasma cannot be absorbed through intact skin)

· Eating food that was contaminated by knives, utensils, cutting boards and other foods that have had contact with raw, contaminated meat

· Drinking water contaminated with Toxoplasma gondii

· Accidentally swallowing the parasite through contact with cat faeces that contain Toxoplasma. This might happen by: 

1) cleaning a cat's litter box when the cat has shed Toxoplasma in its faeces 

2) touching or ingesting anything that has come into contact with cat faeces that contain Toxoplasma
3) accidentally ingesting contaminated soil (e.g., not washing hands after gardening or eating unwashed fruits or vegetables from a garden)

· Mother-to-child (congenital) transmission.

How can I prevent toxoplasmosis?
There are several general sanitation and food safety steps you can take to reduce your chances of becoming infected with Toxoplasma gondii.

· Cook food to safe temperatures. A food thermometer should be used to measure the internal temperature of cooked meat. Do not sample meat until it is cooked. USDA recommends the following for meat preparation

· For Whole Cuts of Meat (excluding poultry) Cook to at least 145° F (63° C) as measured with a food thermometer placed in the thickest part of the meat, then allow the meat to rest* for three minutes before carving or consuming

· For Ground Meat (excluding poultry) Cook to at least 160° F (71° C); ground meats do not require a rest time[i]

· For All Poultry (whole cuts and ground) Cook to at least 165° F (74° C), and for whole poultry allow the meat to rest* for three minutes before carving or consuming

· Freeze meat for several days at sub-zero (0° F) temperatures before cooking to greatly reduce chance of infection

· Peel or wash fruits and vegetables thoroughly before eating.

· Wash cutting boards, dishes, counters, utensils, and hands with hot soapy water after contact with raw meat, poultry, seafood, or unwashed fruits or vegetables

· Wear gloves when gardening and during any contact with soil or sand because it might be contaminated with cat faeces that contain Toxoplasma. Wash hands with soap and warm water after gardening or contact with soil or sand

· Teach children the importance of washing hands to prevent infection and keep your outdoor sandboxes covered. 

If I am at risk, can I keep my cat?
Yes, you may keep your cat if you are a person at risk for a severe infection (e.g., you have a weakened immune system or are pregnant); however, there are several safety precautions to avoid being exposed to Toxoplasma gondii:

· Ensure the cat litter box is changed daily. The Toxoplasma parasite does not become infectious until 1 to 5 days after it is shed in a cat's faeces

· If you are pregnant or immunocompromised:

1. Avoid changing cat litter if possible. If no one else can perform the task, wear disposable gloves and wash your hands with soap and warm water afterwards.
2. Keep cats indoors.
3. Do not adopt or handle stray cats, especially kittens. Do not get a new cat while you are pregnant

· Feed cats only canned or dried commercial food or well-cooked table food, not raw or undercooked meats

· Keep your outdoor sandboxes covered.

Once infected with Toxoplasma is my cat always able to spread the infection to me?

No, cats only spread Toxoplasma in their faeces for a few weeks following infection with the parasite. Like humans, cats rarely have symptoms when first infected, so most people do not know if their cat has been infected. The infection will go away on its own therefore it does not help to have your cat or your cat's faeces tested for Toxoplasma.

[i] According to USDA, "A 'rest time' is the amount of time the product remains at the final temperature, after it has been removed from a grill, oven, or other heat source. During the three minutes after meat is removed from the heat source, its temperature remains constant or continues to rise, which destroys pathogens."