Modern life exposes us to chemicals every second - from the food we eat and the water we drink to the everyday products we use, and even the air we breathe.

But the problem, says natural health campaigner Anna Rodgers, is that they're not just chemicals - they're toxins, or in other words, poisons.

People come into contact with some 80,000 toxins a year, she says, and they're damaging our health.

Rodgers is not a scientist, doctor or dietician, though she describes herself as an "independent researcher" and she's so concerned about toxins that she spent two years writing her new book, Toxic World Toxic People, to highlight the problem and explain how to minimise exposure.

"I'm not an expert, but I'm someone who's passionate about getting the discussion about toxins going," she explains. "Throughout history, doctors and scientists have told us lies about what's healthy and what's not, and if they knew everything we would not be sick today. It's absolutely bonkers how many toxins there are to be concerned about."

Toxins weren't really a problem until after World War II, she believes, when chemicals developed for use in the war began being used in industry. Now they can be found in countless products including food, cosmetics, cleaning products, building materials - and even in the air and water.

"Most things these days aren't at all natural, and we're surrounded by plastics," says Rodgers. "It's out of control."

Traces of medication have even been found in water supplies, she adds, and she's concerned about the lack of testing for many of the toxic contents we're exposed to. With cancer rates on the rise, Rodgers feels certain that the two things are linked. "I want to know what I'm putting on my skin, and what I'm eating, and what I can do to limit my chances of getting cancer, because it really is an epidemic," she says.

There are far too many toxins for her to discuss all of them, she says, but her book focuses on the main ones. So what are they?

TOXIC OVERLOAD

Aluminium is one of the main toxic threats, says Rodgers, who notes that exposure to the chemical element has been linked with Alzheimer's Disease as it can attack nerves in the brain. It has also been linked with bone density problems and is found in numerous foods, including bread, processed cheese, self-raising flour and tinned foods, such as tinned tomatoes, as well as in certain medications.

Lead, Rodgers says, is another cause for concern and is particularly dangerous to children, possibly linked with behavioural problems, Alzheimer's in later life, memory and coordination problems. It can also reduce red blood cell count and affect bone density. People can be exposed to it through old lead-based paint on walls and old pipes in houses.

Mercury, though, she says is "even worse" than aluminium and lead. It's found in air dust particles, water, (and therefore in fish) and used in certain vaccines and dental fillings - which Rodgers claims can leak into the body and contribute to triggering a host of illnesses, including cardiovascular disease, allergies and chronic fatigue syndrome. Plus, t oo much mercury can affect the brain, immune system and trigger autoimmune conditions.

WHY ARE TOXINS ALLOWED?

In Rodgers' eyes, widespread acceptance of toxins is linked to money, "irresponsible companies", poor regulation, and the fact that while a small amount of one chemical on its own may not cause ill health, problems can arise when it accumulates in the body and is combined with other chemicals.

"There are organisations out there that have a vested interest in keeping the public naive," she claims. "I think there are cover-ups, and a lot of ignorance as well, where doctors and scientists believe chemicals aren't harming us because they're taught that the poison is in the dose, b ut there are so many studies showing that it's not just about the dose, it's about the accumulation [over time]."

She adds: "A chemical on its own might not be harmful, but once you add it to another chemical, that can be when the damage occurs."

WHAT CAN BE DONE?

Rodgers admits that it's difficult to know what the answer is: "Ideally, I'd like a world where we try and stop using these chemicals. But some of them have made our lives better - we couldn't stop flying or using cars, for example, even though the pollution is a huge problem."

She suggests that some people can cope with exposure to toxins, while others are more quickly affected. But there's no way of telling who's sensitive and who's not. Rodgers herself is very sensitive to chemicals, she says, and a major reason for writing the book was that she suffered from depression, chronic fatigue and a number of other health problems by the age of 25.

Having cut out as many toxins as she can, she says she's now "100% better" and advises others do the same.

"Awareness is key," she says. "It's all about learning where these toxins are coming from, and making different purchases of products that are not using these awful chemicals." Suggestions can be found in her book, including cosmetics, cleaning products and foods which contain few, or no, toxins. Rodgers also recommends people avoid tinned food, eliminate fish, reduce their meat intake and buy organic only, as well as trying to actively detox.

SHOULD WE BE WORRIED?

While there's no question that toxins exist, not everybody shares Rodgers' level of concern.

Toxicologist Professor Alan Boobis points out: "We have been actively detoxifying potentially harmful chemicals in our diet for millennia, at much greater levels than those to which we are now exposed from man-made sources."

Boobis, a professor of biochemical pharmacology, and director of the Public Health England Toxicology Unit at Imperial College London, explains that the Stockholm Convention on Persistent Organic Pollutants (POPs), a global treaty to protect human health and the environment from certain chemicals, which became effective in 2004, means that "very few chemicals in use today accumulate in the body".

He stresses that advice from organisations like the Food Standards Agency (FSA), the European Food Safety Authority (EFSA) and the World Health Organisation (WHO), on acceptable exposures to chemicals takes into account possible accumulation in the body. "There is no good evidence that exposure to chemicals at levels considered acceptable by regulatory authorities is associated with cancer or other illnesses," he says. "Indeed, the focus on environmental chemicals can detract from addressing the major risk factors that have been identified."

As for diet, he points out that while there are certain risks associated with seafood, these are well recognised, and dietary advice from the FSA and others balance the risks against the undoubted benefits of such food. "Complete elimination of fish from the diet would cause considerably more harm than good," Boobis warns.

Tinned food and conventionally farmed foods serve an important function, he says, enabling ready access to affordable, nutritious food, and he stresses: "There is no good evidence that tinned food or conventionally farmed foods are a cause of ill health in consumers."

:: Toxic World Toxic People is published by Soul Rocks on June 27, priced £21.99