LETTER OF THE WEEK: Clare Island's crypto-stricken drinking water

Sir,

MAYO County Council, in conjunction with Water Ireland and the Environmental Protection Agency (EPA), announced that Clare Island's drinking water is contaminated by the protozoan parasite, cryptosporidium (crypto).

Islanders will have to boil their water or drink bottled water for an indefinite period while the effects on tourism, following on the heels of Covid-19, doesn't bear thinking about.

But when it comes to crypto contamination, local authorities rarely give the public the full facts.

When 242 patients were hospitalised by Galway's crypto epidemic in 2007, it cost the city €23m (today's equivalent) and devastated tourism for five months.

Despite Galway County Council having failed to regularly test the city's water supply, it initially broadcast that the outbreak was due to 'global warming' or 'a horse floating somewhere in Lough Corrib"! Truth became the epidemic's first casualty.

This same parasite had Ennis's citizens boiling their water for a staggering two years.

This highly infective bug normally lives in the entrails of agricultural animals and reproduces every 12 hours. Newly-born lambs and calves are packed with crypto; each animal excretes 50 billion (yes, that's billion) parasites soon after birth.

These young parasites resemble tough, microspic-sized pellets – called oocytes – which survive in water or on land for 120 days, hence the effects of the island's outbreak will be felt for some time.

I won't bore you with the six stages of the crypto's life cycle – except to say that within 12 hours of being swallowed by humans, it burrows into the wall of the gut, causing diarrhoea, sickness, fever, sometimes hospitalisation.

The rarer type, cryptosporidium hominis, can be spread by humans (as happened in the Galway epidemic) but local authorities are coy about telling you that the agricultural cryptosporidium parvum is responsible for almost all Irish outbreaks.

The main risk factors in contracting crypto are contact with farm animals (especially young stock) or drinking water infected by animal faeces/slurry/silage effluent, etc.

The parasite may also be found in wells or communal water supplies contaminated with animal faeces or agricultural run-offs.

Most water-contaminating bacteria are routinely killed by adding chlorine to infected water supplies but crypto is immune to chemical treatments.

To remove these parasite requires the installation of expensive water-filtration systems, which Mayo County Council is unlikely to fund because of cost.

Clare Island is not alone - the EPA has identified over 200 other water supplies as being similarly unfit for purpose.

The question is – has the island's surge in the number of agricultural animals been balanced by increased attention to proper practice.

All liquid wastes eventually end up somewhere so when it comes to getting rid of agricultural liquors, out of sight does not mean out of mind.

Remember, one teaspoon of manure may contain enough crypto to hospitalise your family for a fortnight.

Despite the watered-down 'facts' issued by the local authorities, agriculture is the major component in the vast majority of crypto outbreaks. That's why Ireland's rate of the crypto infection is the highest in the EU – treble that of Britain!

The EPA's Director of Environmental Sustainability, Sharon Finnegan, claims that agricultural growth is 'happening at the expense of the environment... we must go beyond improving efficiencies by breaking the link between animal numbers and deteriorated water quality'.

In the meanwhile, Clare Island must share the same stigma as do many Irish communities – its drinking water has not been striken by some inexplicable, mysterious or devil-sent malady, it has been sacrificed on the altar of agriculture.

Yours,

Dr. Roderick O'Sullivan, BDS, MSc, Dip Astro'omy, MA,

London and Westport.