For all the newspaper columns devoted to mercury, mobile phones and mad-cow disease, most of us are still in the dark about the genuine risks. We've separated the certainties from the scare-mongering to unravel the truth about some of the world's biggest health scares. You'll have heard of some of them, others not. But they're all worth knowing about...BAD HEALTH - A BRIEF HISTORY
Leprosy dates back almost to the dawn of time and is estimated to have killed more than 11 million people to date, with other three million cases remaining untreated. It's a bacterial infection of the skin and nerves and causes severe deformity. Brought to Britain by Crusaders in 1230, it spread through Europe during the 15'" century, leading to the establishment of an estimated 20,000 leper colonies. Sufferers who tried to leave the colonies were hanged, burnt or buried alive. When treated with modern drugs, leprosy can be cured within three months.
No-one knows when mosquitoes began injecting humans with the plasmodium parasites that causes malaria but it remains one of the most persistently deadly disease in the world. It's a constantly changing parasite that adapts in response to attacks from the body's natural defences, causing fever, coma and death. It's thought that malaria has killed more people than all human conflicts combined. Today, 45 percent of the world's population is at risk and one person dies from the disease every 12 seconds. Currently there is no reliable and safe vaccine.
1870s SMALL POX
Smallpox swept through Europe during the 17th and 18th centuries, killing more than 100 million people. Those who survived were scarred with the distinctive pits in their skin. Even though it continued to spring up all around the world throughout the following century, by the Sixties a mass vaccination programme had successfully eliminated the disease. As a result, humans have all but lost any natural immunity to small pox. The virus itself still exists in various laboratories around the world.
MERCURY IN FISH?
THE HEALTH RISKS of mercury and roundworm in fish aren't well publicised, but the dangers they pose were acknowledged in 1960 when tins of tuna were found to contain high levels of mercury. The main source was meat from bigger, older tuna, which had fed on huge amounts of mercury-absorbing plankton. Today, producers use younger fish, which have lower mercury levels. While these concentrations present no health risks to adults, they may be dangerous to mothers-to-be as the metal can affect the nervous system of the foetus.
Meanwhile, roundworm can cause inflammation, fever, colic and intestinal blockages. Even after strict regulations were passed by the European Union in 1988, roundworm (or their larvae) were still found in more than a third of all fish spot-checked in Germany in 1997. The most contaminated fish is green herring - which must be gutted before eating - but cod is often also infected. Since you can't see the roundworm, the only way to ensure they're killed is by cooking the fish well. Temperatures above 60°C will take care of the worms, while smoke-drying, marinading or freezing the fish below minus 20°C will also kill them.
DROP THAT BEEF!
FOLLOWING DOZENS OF government inquiries in the UK, the culling of almost five million cattle and 92 human fatalities, scientists remain divided over the exact cause of variant-Creutzfeldt-Jacob disease (vCJD) in humans and bovine spongiform encephalopathy (BSE), more commonly known as mad-cow disease, in cattle. What we do know is that humans who contract vCJD die a painful death.
The accepted theory is that the two related diseases are caused by rogue "prion" proteins, which can turn brain cells into mush. Most scientists believe that these prions were created by feeding cattle the remains of sheep suffering from another brain disease, scrapie.Fortunately, Australia and New Zealand are two of only five countries in the world to be certified BSE-free - due in no small part to be banning of feed imports back in the Sixties. And fortunately, they've also never had a case of vCJD.
people are possibly at risk?
If you're one of the millions that went to the UK between 1980 and 1996, you're in the firing line. Estimates of the total number of people in the UK who might develop the current strain of vCJD vary from 100 - suggesting the worst may be over - to a staggering 136,000. The truth? No-one really knows.
Is there a way to make the beef
safe to eat?
No. And there's no way to detect the disease at an early stage either.
Is it safe to eat beef?
As mentioned, beef from Australia and New Zealand has a clean bill of health and even in Britain, beef is currently safer than at any time during the Eighties. However, between 1985 and 1989 - when the most infectious tissues, such as the brain and spinal chord, were still being used in food - 446,000 BSE-infected cows were eaten. The UK's Ministry of Agriculture, Farming and Fisheries claims that there should now be "NO RISK" of contracting vCJD from beef.
THAT MOBILE'S COOKING YOUR BRAIN
MOBILE PHONES WORK by intercepting microwaves from nearby "base camps" or stations. Because they have a longer wavelength than radio waves, microwaves can be absorbed by tissues, especially watery tissues.
Should you worry?
Currently, there's no scientific evidence to prove that mobile phones produce adverse health effects. But this doesn't mean users should permanently glue their mobiles to their head. There are always limits to scientific knowledge while the possibility of effects of such low-level radio-frequency (RF) exposure have not been clearly established, there is still a need for research in this area.
WHAT ABOUT GM FOOD?
ANIMALS AND CROPS have been selectively bred for thousands of years in pursuit of bigger and better food, but the fact that we're now doing it at a genetic level is making some consumer uneasy.
However, some countries don't understand the fuss. For example, the US and China have been eating genetically modified (GM) foods since 1995, without a single recorded case of health problems.
From 1986 to 1997, about 25,000 GM food trials were conducted on more than 60 crops in 45 countries and no adverse results were recorded. GM food supporters argue that genetic engineering allows them to create exactly what they need. They also claim GM foods are needed to meet the global good demand. And while many fear that GM foods will hurt the environment, this may not be true. Some developed grains don't require traditional pesticides and chemicals that destroy the environment.