BAGHDAD: A study examining the causes of a dramatic rise in birth defects in the Iraqi city of Falluja has for the first time concluded that genetic damage could have been caused by weaponry used in US assaults that took place six years ago.

The research confirms earlier estimates revealed by The Guardian of an unexplained rise in cancers and chronic neural-tube, cardiac and skeletal defects in newborns.

The researchers found that malformations were almost 11 times higher than normal rates, and rose to unprecedented levels in the first half of last year, a period not surveyed in earlier reports.

The findings, to be published in the International Journal of Environmental Research and Public Health next week, precedes a much awaited World Health Organisation study of Falluja's genetic health.

They follow two alarming earlier studies, one of which found a distortion in the gender ratio of newborns since Iraq was invaded in 2003 - a 15 per cent drop in births of boys.

''We suspect that the population is chronically exposed to an environmental agent,'' said one of the report's authors, Mozhgan Savabieasfahani, an environmental toxicologist.

''We don't know what that environmental factor is, but we are doing more tests to find out.''

The report identifies metals as potential contaminating agents afflicting the city's residents, especially pregnant mothers.

''Metals are involved in regulating genome stability,'' the study says. ''As environmental effectors, metals are potentially good candidates to cause birth defects.''

The findings are likely to prompt further speculation that the defects were caused by depleted uranium rounds, which were heavily used in two large battles in the city in April and November 2004. The rounds, which contain ionising radiation, are a core component of the armouries of numerous militaries and militias.

Their effects have long been called into question. Some scientists say they leave behind a toxic residue, caused when the round - either from an assault rifle or an artillery piece - bursts through its target.

However, no evidence has been produced that proves this, and some researchers instead claim that depleted uranium has been demonstrably proven not to be a contaminant.

The report acknowledges that other battlefield residues may also be responsible for the birth defects. ''Many known war contaminants have the potential to interfere with normal embryonic and foetal development,'' the report says. ''The devastating effect of dioxins on the reproductive health of the Vietnamese people is well known.''

The latest Falluja study, conducted by a paediatrician at Falluja general hospital, surveyed 55 families with seriously deformed newborns between May and August.

In May, 15 per cent of the 547 babies born had birth defects. In the same period, 11 per cent of babies were born at less than 30 weeks, and 14 per cent of foetuses spontaneously aborted.

The researchers believe the figures understate what they describe as an epidemic of abnormalities, because many babies in Falluja are born at home.

The US military has long denied that it is responsible for any contaminant left behind in Falluja, or elsewhere in Iraq, as it continues to withdraw from the country it has occupied for almost eight years.

It has said that Iraqis who want to file a complaint are welcome to do so. Several families told The Guardian in 2009 that they had filed complaints but had not received replies.

Guardian News & Media