SPRAY TELL: Abandoned Orchards Reveal Arsenic

Arsenic can be found everywhere in nature, but it’s most commonly found in the form of sulfides combined with the sulfides of ores of other metals, coals and sediments. Arsenic poisonings are rare and usually accidental, but chronic exposure to arsenicals can be dangerous, in particular with the delayed effects which can lead to diseases like cancer. That’s why it’s become increasingly important for environmentalists to focus on one major area of concern that on the surface traditionally engenders feelings of beauty, health and safety: abandoned orchards.

Most of us enjoy the sight of an abandoned orchard with their orderly planted rows of trees but few can imagine the dangers lurking just below the surface. Toxic pesticides used more than 100 years ago could be to blame for arsenic contamination in drinking water. Pesticides were used heavily to protect fruit trees but it was never fully understood whether the arsenic ingredient could travel to groundwater and pollute wells. Some scientists believed that arsenic wasn’t water soluble enough to break free from the soil but rainfall tests have shown that arsenic could filter into rainwater which creates a direct route into wells. Identifying where arsenic could be an issue is also difficult given the widespread use of pesticides and the high number of orchards that exist. However, protection against arsenic remains fairly a straightforward proposition: test regularly since long-term exposure is the major concern.

Fruit orchards aren’t the only places where pesticides containing arsenic were used extensively. A wide range of agricultural industries treated their crops with pesticides and now much of that land is being converted into residential properties. Between the years of 1992 and 1997, more than 6 million acres of American farmland was turned into home communities. Still, orchards garner the most attention from environmental groups due to the toxicity caused by arsenical pesticides like lead arsenate (LA) which was a very popular weapon in the fight against insect infestation and damage.

Originally introduced to combat the gypsy moth, LA became the treatment of choice against the codling moth which is a fierce pest found in apple orchards. The relentless assaults suffered by these moths required growers to apply pesticide chemicals often and in high concentrations over a long period of time. Compounding the issue is that these arsenical pesticides were specifically manufactured to be just as relentless, which is why we’re seeing contamination problems all these many years later. Once LA reached the soul, the lead separated, and the arsenic bound to the soil. Lead is barely soluble, so it remained no deeper than a foot below the topsoil. Arsenic, being somewhat more soluble, still moves in water and can be found as deep as a meter below. Disturbing the soil through building can create erosion which can send arsenal into the surface waters, increasing the risk.

So how risky is it to live atop contaminated old orchard soil? Without direct contact, the risk is very manageable. Again, awareness, testing and proper filtration is key. The biggest issue that faces us now is the scope of the problem since millions of acres across the United States are involved and locating “hotspot” areas can be difficult.  Cleanup involves a number of methods, from excavation, soil blending, turfin it, and even adding phosphorus. So, while living on an historic orchard property may not constitute a significant health risk, once the area has been identified as contaminated you can definitely expect your taxes to go up.

With Graver, heavy metals removal from community water supplies can be done with water filtration systems that have been engineered with superior purification standards. For more information on arsenic removal from water or lead removal from water, visit our page on treating drinking water with MetSorb® Adsorbent Media.

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