Fires, explosions and chemical leaks have resulted in hundreds of tons of toxic substances being released into the environment to pollute the drinking water of millions of people along the banks of the Danube and its tributaries.
Mervyn Richardson, a freelance consultant for the UN and an expert on toxic chemicals, warned that there would be a significant increase in the number of children with congenital malformations as a result of their parents drinking contaminated water.
Mr Richardson, the first Western scientist to study the pollution caused by the war, visited 18 war-ravaged towns and inspected 50 destroyed installations on a mission last year funded by the UN Industrial Development Organisation for the Republic of Croatia.
His unpublished report details a catalogue of disasters that include leaking electrical installations spreading highly dangerous dioxins and PCBs - polychlorinated biphenyls - and the detonation of ammunition dumps releasing toxic heavy metals.
An explosion in August 1992 at an oil refinery at Sisak, a town 35 miles south of Zagreb, released 95,000 tons of crude oil and other pollutants into the surrounding area. A 500-mile oil slick ran from the refinery down the River Sava, which flows into the Danube, and has ended up polluting the Danube delta, an area of outstanding scientific interest more than 725 miles away on the shores of the Black Sea.
A huge 'wall of fire' at the dump had left the northern bank of the Sava blackened for 3 miles with cancer-causing polyaromatic hydrocarbons, Mr Richardson said.
Much of this toxic pollution had been washed into the river, and people living downstream in Serbia, Bulgaria and Romania were undoubtedly drinking contaminated water because the authorities there did not routinely monitor for polyaromatic hydrocarbons, Mr Richardson said. This and other incidents have gone largely unreported.
One of the worst pollution incidents occurred after the destruction of a chemicals factory at Osijek. In addition to the manufacture of detergents and other household chemicals, the factory housed 100 tons of the active ingredients used to make pesticides. 'Every time it rains, these highly dangerous substances are being washed into the Drava River, another tributary of the Danube, exceeding European safety levels,' Mr Richardson said.
Three large ammunition dumps were destroyed in the war, one of the biggest being at Ostarije, south-west of Zagreb, where up to 25,000 tons of weapons were stored. The explosion contaminated a large area with ammunition and residues of chemical weapons.
Scientists from the University of Zagreb taking soil samples from the area last year found 'almost total devastation', with wild animals 'tottering about deaf and blind' and the widespread dispersal of such toxic metals as mercury, lead and cadmium, which can linger in the environment for decades.
Mr Richardson fears that these heavy metals will be leached into underground rivers and be swept towards the Croatian coast of the Adriatic, where the water re-emerges and is used for drinking.
Another problem is the deliberate burning or shelling of electrical installations, such as transformers and condensers, in more than 250 towns in Croatia.
In Dubrovnik, Mr Richardson estimates, at least five tons of PCBs were released as a result of electrical transformers there being destroyed. Dioxins, a highly toxic group of chemicals, were also released when the PCBs in the transformers caught fire.