Arsenic, it sounds like the poison of choice from a gothic romance novel. Odorless and tasteless, it was once known as “the poison of kings and the king of poisons”. In 55CE, Nero used it to murder his stepbrother, Tiberius Britannicus, so he could become Emperor of Rome. Arsenic was frequently used for murder because there was no test to detect it until 1836. The symptoms of arsenic poisoning are not very specific, making it the near perfect weapon. Arsenic also has a place in medical history as a treatment for syphilis. So why is it important for real estate professionals to know about arsenic in wood and water?
Arsenic is naturally found in soil and rocks. It is highly toxic in its inorganic form. Arsenic is a metalloid element widely distributed in the Earth’s crust. Its just about everywhere. Most people get a little arsenic every day in the food they eat and the water they drink. It is commonly found in the ground water of New England. Private wells should be tested regularly for arsenic and other contaminants. Preliminary well water analysis typically does not test for arsenic. Private dug wells are most at risk for containing inorganic arsenic. An effective method to avoid arsenic contamination is to sink wells 500 feet or deeper to reach purer waters. The process of removal is called adsorption, arsenic sticks to the surfaces of deep sediment particles and is naturally removed from the ground water.
The EPA drinking water standard, since 2006, set the maximum level of inorganic arsenic to 10 parts per billion. There is no arsenic standard for private wells. The FDA set the same 10 ppb standards for bottled water in 2005. The FDA also set “level of concern” at 23 ppb for apple & pear juices and began blocking imports that exceed this level. Studies have shown that low-level arsenic exposure at concentrations of 100 parts per billion compromises the initial immune response to the Swine Flu (H1N1). It is estimated that over 7% of private wells are above 10ppb.
The toxicity of arsenic to insects, bacteria and fungi led to its use as a wood preservative in the 1930s. Wood was treated with chromated copper arsenate (CCA) for next 75 years. Increased knowledge of the toxicity of arsenic led to a ban and phasing out of CCA in consumer products in 2004. Although discontinued, CCA treated wood is the most concerning to the public. Most of the older pressure treated wood was treated with CCA. This type of wood was used extensively as structural and outdoor building material. The concern is arsenic being absorbed through the skin or on the skin and then touching the mouth. Although this is not a major route of ingestion. There are even studies showing that arsenic leached from this type of pressure treated wood to the surrounding soil.
Arsenic is absorbed by all plants, but is more concentrated in leafy vegetables, rice, apple & grape juice and seafood. People who are exposed to too much arsenic, over many years, are likely to get cancer and skin lesions. Epidemiological studies have suggested a correlation between arsenic exposure and diabetes.
You cannot remove arsenic by boiling the water or using chlorine bleach. Methods such as reverse osmosis, ultra-filtration or ion exchange should be considered to treat water. Replacement of older pressure treated wood for areas where humans come in close contact with the wood, such as decking, should be replaced. Contact the local or state health department for recommended procedures. Disclosures are required by many states for Arsenic in wood and/or water. At the end of the day, the real estate professional is wise to understand this environmental hazard and properly disclose it.
Shannon Aldrich Whaley, The Real Estate Class (c) 2021