Decaying World War II Bombs Threaten Health and Environment in Solomon Islands, Study Finds

Coastal communities across the Solomon Islands are facing growing health and environmental risks as aging World War II bombs continue to release toxic chemicals into land and sea, according to new research.

A news release from the United Nations Development Programme in the Solomon Islands highlights findings from an Environmental Impact Assessment, the first of its kind in the Pacific, which examined how decaying unexploded ordnance is contaminating surrounding ecosystems.

Unexploded World War II ordnance remains in areas across Solomon Islands.

The study was conducted by scientists from The University of Queensland, with support from the UNDP and funding from the Government of Japan.

More than 80 years after World War II, thousands of bombs, shells and other munitions remain scattered across the country. As these weapons corrode, they release toxic heavy metals and explosive chemicals into soil, waterways and coastal environments.

Researchers identified elevated levels of arsenic, lead, cadmium and mercury at sites containing unexploded bombs. They also detected explosive compounds such as TNT and PETN.

Contamination detected in seafood

The study found traces of explosive chemicals in marine life, including shellfish collected from nearshore waters. Communities and local clinics have reported health symptoms linked to seafood consumption in affected areas, including skin rashes, ulcers, vomiting, diarrhoea and neurological issues. Some cases have also been observed in breastfeeding infants.

Lead researcher Stacey Pizzino warned that the risks are increasing as the bombs continue to break down.

Researchers tested samples at selected sites.

“The health risk from World War II ordnance is rising as it degrades and releases heavy metals into the environment,” she said. “Communities are already reporting illnesses that may be linked to exposure to these toxins.”

While testing was conducted at selected locations and does not represent the entire country, the findings indicate that contamination is likely wherever unexploded ordnance interacts with soil, water or marine ecosystems.

A legacy of war still present

The Solomon Islands was the site of intense fighting during World War II, including the pivotal Guadalcanal Campaign. Today, the threat from unexploded bombs remains widespread.

According to the Royal Solomon Islands Police Force, 7,773 unexploded ordnance incidents were reported between 2011 and 2025, most involving live explosives. Many of these are located near villages, gardens and fishing areas.

Climate change worsening the risk

Researchers say climate change is compounding the problem. Flooding, storms and coastal erosion can expose buried bombs, accelerate corrosion and spread contaminated sediments into water sources and marine habitats. Warmer and more acidic ocean conditions may also increase the release of toxic substances.

More than half of known bomb sites are located within one kilometre of the coast, making them especially vulnerable to climate-related impacts.

Call for urgent action

The report calls for accelerated bomb clearance in high-risk areas, along with long-term monitoring of water quality and seafood safety. It also recommends improved national mapping of unexploded ordnance.

Raluca Eddon, Deputy Resident Representative of the United Nations Development Programme in the Solomon Islands, said the findings underscore the urgency of action.

“Time is running out as hazardous chemicals continue to leak into the environment, affecting reefs, marine life and coastal communities,” she said.

The findings were presented in collaboration with the Ministry of Police, National Security and Correctional Services. Acting Permanent Secretary George Bogese described the report as a valuable resource for both the country and the wider region, acknowledging ongoing support from Japan.

For many communities, the study highlights that the environmental and health impacts of a war fought more than eight decades ago are still unfolding today.

Source: UNDP Solomon Islands