Free-range eggs 'contain five times as much pollution as those from caged birds'

 | Mail Online

Ethical shoppers are being warned that free-range eggs may be less healthy than those from caged birds.

Scientists found that free-range eggs contain at least five times higher levels of certain pollutants than normal eggs.

Around 17 per cent of the free range eggs had levels that European regulators would have deemed unsafe for consumption.

The study was carried out in Taiwan but the findings will raise concerns about the safety of eating free-range chicken eggs in the UK.

Free-range chickens are those that have continuous access to fresh air, sunshine, and exercise, in contrast to chickens that are confined to cages.

But scientists suspect that free-range chickens may risk getting higher levels of exposure to environmental pollutants, particularly PCDDs and PCDFs, potentially toxic substances that are produced as by-products of burning waste.

Also known as dioxins, these substances may cause a wide range of health problems in humans, including reproductive and developmental problems and cancer.

They found that the free-range eggs contained 5.7 times higher levels of PCDDs and PCDFs than the regular eggs.

The scientists collected six free-range eggs and 12 regular eggs from farms and markets in Taiwan and analysed the eggs for their content of dioxins.

Taiwan is a heavily populated, industrialized island with many of the municipal incinerators that release PCDDs and PCDFs.

But the authors of the report warned that the issue could be more widespread.

They wrote: 'The issue of contamination in free range eggs could be a global issue, and more research should be done to identify the factors from the external environment that influence and modify the PCDD/F levels in eggs from free range hens.'

The researchers believe the free range eggs contain pollutants which the hens pick up from being free to feed in the open.

They said the chemicals were present in 'feedstuffs, soil, plants, worms and insects'.

Demand for eggs from free-range chickens has increased steadily due to their supposed better nutritional qualities, including higher levels of certain healthy fats.

The findings appear in the Journal of Agricultural and Food Chemistry.