Is the food still safe to eat?

 For the past few days, New Zealand has suffered from high winds and extensive flooding as a result of Cyclone Gabrielle, which in some coastal areas has coincided with high tides.  Many areas have been without power for extended periods and thousands of people have had to leave their homes, in some cases being rescued from the roofs of their houses.

I was interviewed by a radio journalist who wanted to ask questions about the safety of food and water. Any food that has been contaminated by the flood waters is, of course, not fit to eat.  But what of foods that were in refrigerators and freezers?

This is a difficult question to answer.  If the power has been off for a few hours and the refrigerator has not been opened, the food will probably be safe to eat, however, some areas are not likely to have power restored for several days.  Some foods, such as yoghurt are naturally preserved by their acid content and will be shelf-stable even at room temperature for a few days.  Hard cheeses will also be safe.  Similarly, milk in sealed bottles will be OK for a couple of days.  Vegetables are also shelf-stable for several days at room temperature, provided that they have not been in the water.  Eggs have their shells to protect the contents, but it would be worth washing the shells to prevent contamination of the contents when they are cracked open.  Perhaps a good guide is to think of supermarket displays - if the food such as fruit, potatoes, tomatoes and cabbages is sold from open counters, it can reasonably be expected to last for several days.

The big concern will be fish and meat.  If the frozen food has thawed out completely, it may still be safe to eat if it is thoroughly cooked.  if the food still has ice crystals in it, refreezing is possible.  Beef and pork steaks are essentially sterile inside, so it is only necessary to cook the outside, remembering to cook the edges too.  Fish is normally sold in fillets, so again, frying or barbecuing will render it safe, however, the food cannot be stored for another few days before consumption.  I would be more concerned about chicken, which is always difficult to cook throughout because of the uneven thickness of drumsticks etc.  In all cases, the critical thing is to get the temperature of the food above about 75C throughout.  This will kill all vegetative (non-sporulated) bacterial cells.  If a thermometer is used, it must be clean and inserted into the thickest part of the food.  More care is required with minced meat.  During the mincing operation, the outside of the meat is mixed in with the interior portions, so thorough cooking is required - medium-rare hamburgers are out! 

Another, though not infallible guide is to look at the food and smell it - if it smells off, then don't eat it.  Things like bacon sometimes become a bit slimy as a result of bacterial growth on the surface.  If it is fried properly, it will be safe to eat, but may have off-flavours.

Of course, canned foods are safe, provided that there are no holes in the can. Similarly, sealed packages of snack foods, such as 'chippies' will be OK to eat and may make the kids feel a bit happier.  It is a good idea always to have a supply of canned foods in the cupboard so that they are available in emergency situations like ours.

Another major concern is water.  Some water treatment plants have been out of action for a couple of days as a result of power outages and some watersheds may have been swamped by flood waters.  A number of water supply authorities have said that the tap water is safe to drink.  However, if there is any doubt about its safety, it should be boiled.  I was asked about water for making up baby formula.  In that situation, I would always recommend using boiled water.  Rural households often collect water from the house roof and store it in large tanks.  In my opinion, this water will be safe, provided that the roof and tanks have not been inundated, but once again, if there is any doubt and the power is on, it should be boiled.

All of these questions will become more relevant when people are allowed to return to their dwellings. There may be a temptation to try to salvage food from refrigerators and cupboards.  If there is any doubt, the safest thing to do is to dump it, as food poisoning will put even more stress on health services at this time.

Our next concern will be resupply.  Many roads are impassable, leaving some towns completely cut off.  Supermarkets are very short on stock, even if they have power to operate the tills.  Foods may be in short supply for a while, but in addition, orchards and vegetable farms have been severely damaged, so shortages will continue for months.  There may be more reliance on imports.

Odd Spot:  if the cyclone were not enough to challenge the population, we also had a magnitude 6.3 earthquake yesterday.  It was centred about 50km NE of Paraparaumu in the North Island, so it was under the sea.  There have been no reports of injuries or damage, but it's something we could all have done without!

Raw water: Is it bullshit?

There is a new fad spreading rapidly in the US.  "Raw water" is the latest craze for health fanatics keen to spend serious money.

What is raw water?  Its proponents claim it is water as nature intended it - unfiltered and untreated, containing minerals from the water source and no chlorine.  One raw water company claims that "all other bottled, filtered, tap, and even spring waters are sterilised with ozone gas, irradiated with UV light, and passed through a submicron filter" and that "blasting water with ozone changes its molecular structure".  Clearly, there is some truth in this statement, but also a lot of nonsense.

Some water sources are indeed safe to consume untreated; others may appear to be so, but are not safe.  In August 2016, over 1000 residents of Havelock North in New Zealand became ill after consuming drinking water from two bores operated by the local council.  Investigations showed that the affected residents had been infected by Campylobacter.  This was not the first time that the bore heads had been found to be contaminated.   The outcome of an extensive investigation was that the water in the bore heads was contaminated with water from an adjoining farm pond on land that had been inundated by heavy rains.  The aquifer was not contained and when the pumps were turned on, water from the pond, probably contaminated with sheep faeces, was drawn into the town supply.  Anecdotal evidence says that the level in the pond dropped when the pumps were turned on.  An immediate response was to chlorinate all water supplied in the area, which annoyed some residents, and the two affected bores were closed.  Water was drawn from other bores in the nearby Hastings area and  the supply has been chlorinated.

I am constantly surprised by people who want to turn back the clock to a time when food and water borne diseases were common, before modern scientific and technological advances made our lives much safer.  Campaigning to ban chlorination of town water is one of those issues.  Consumption of raw milk is another one of those desires that can lead to illness.

However, I am also reminded constantly that many rural areas are not serviced by mains water and wastes are treated on site in septic tanks, then discharged to the land.  Our house on our own lifestyle farm collects water from the roof and stores it in 36,000L tanks.  There is no filtration, chemical or UV treatment.  We, like many other rural dwellers, are thereby deliberately exposing ourselves to risk, though there is no alternative other than boiling water or buying bottled water for drinking.  The only thing I can say is that since moving to the farm over 30 years ago, we have never suffered from gastrointestinal illness.

Where does this leave us?  Treated tap water is probably the safest water supply.  Experience shows that rural tank water is usually safe, though it is not sterile; provided that the tanks are protected from contamination by animals or from septic tanks, there is little to fear from drinking it.  The perceived benefits of bottled raw water may be illusory, and the marketing hype criticising filtration and ultraviolet treatment of spring waters is just plain misleading.  Those getting the most benefit from bottled raw water are the suppliers.

Third World water supply

Residents of this village have been boiling their water for drinking for the past four years.  They have just been told that they can expect to do this for at least another ten years, because upgrading the supply is not a priority.

The village water supply, which is drawn from an open stream, was described by the regional mayor as "Potentially safe to drink, most of the time".  There is the possibility of Giardia and Cryptosporidium contamination in the water supply.  Doesn't sound too good does it?

The UN General Assembly declared on 28th July 2010 that safe and clean drinking water and sanitation is a human right essential to the full enjoyment of life and all other human rights. The General Assembly also voiced deep concern that almost 900 million people worldwide do not have access to clean water.

So, is this village in Africa, South America, or India?  No.  It's in the North Island of New Zealand.  That puts these residents on a par with many Third World countries.

Mathew Grocot, writing in the Manawatu Standard this week, reports that the Horowhenua District Mayor told the local residents association that the minimum period before residents could expect to see a tangible improvement in their water supply was ten years.  Water and sewage projects in the district would cost more than $100 million over the next 20 years.  Another town in the district had priority for upgrade of its water and sewage systems.

Some residents were predictably annoyed when told that other infrastructure projects, including a community centre, library and park upgrades in other towns had priority.  When asked why these projects were deemed more important than the village water supply, the mayor said that if these community facilities were not provided, people would not want to live in the district.

Seems to me that crap in the water is a really good reason not to live there.