Plans to build a third runway at Heathrow Airport could have significant negative effects on the health and wellbeing of up to three million people living nearby, according to a new government-commissioned report released as ministers push ahead with airport expansion plans.
The assessment, carried out for the Department for Transport (DfT) by consultancy Aecom, found that both the construction and operation of a new runway could create “major adverse” impacts for communities around the airport.
The report warns that expansion could worsen noise pollution and air quality while also affecting access to housing, healthcare, education, transport and green spaces. It further highlights concerns over water quality, community cohesion, local landscapes and the UK’s efforts to tackle climate change.
While the analysis identified potential economic benefits, including increased employment opportunities, income growth and improved training prospects, it concluded that environmental and social impacts are likely to outweigh those gains for many local residents.
“Adverse effects are considered likely with regard to the other determinants which cover environmental and social considerations, and many of these have potential to be significant,” the report stated.
The assessment also noted that although mitigation measures could reduce some of the damage, the impacts cannot be completely eliminated.
A Department for Transport spokesperson stressed that the findings reflected a scenario in which no mitigation measures were introduced.
“The health impact assessment describes what would happen if a third runway was built without any mitigations being put in place – mitigations we are actively working to implement,” the spokesperson said.
“We know communities around Heathrow have legitimate concerns about expansion.”
The findings were published alongside the government’s latest consultation on a draft national policy statement supporting Heathrow’s expansion.
Transport Secretary Heidi Alexander described the consultation as a key milestone in the project.
“Today’s consultation is a positive step towards realising the benefits of a third runway,” she said.
“We are determined to move quickly and responsibly to set a framework for future expansion at Heathrow that will meet the needs of local people and the country.”
The proposed Heathrow expansion would involve constructing a new 3,500-metre runway, relocating part of the M25 motorway and acquiring around 800 homes through compulsory purchase.
The £33 billion project could increase Heathrow’s annual capacity to as many as 756,000 flights and 150 million passengers.
Chancellor Rachel Reeves has been one of the strongest supporters of the project, arguing that it would deliver major economic benefits.
“Growth is this government’s top priority, and we are backing the builders to get Britain moving,” Reeves said.
She added that an expanded Heathrow could support more than 60,000 jobs and generate up to £42 billion in economic benefits.
Speaking at a conference in London, Reeves said: “Somebody had to bite the bullet.”
“I am determined that by the time of the next election, there are spades in the ground.”
Heathrow chief executive Thomas Woldbye also welcomed the latest developments, calling the expansion plans a sign of progress.
“Our plan is privately funded by some of the largest investors in the world, widely supported by businesses, trade unions and communities across the country and it’s ready to go after years of scrutiny,” he said.
However, campaigners remain strongly opposed to the project.
Paul McGuinness, chair of the No 3rd Runway Coalition, warned that local communities face a “decade of destruction” from demolition works and infrastructure changes before any runway becomes operational.
Environmental groups also criticised the speed of the government’s consultation process, arguing that residents living under Heathrow’s flight paths are not being given enough opportunity to voice their concerns.
The consultation marks the latest stage in what remains one of the UK’s most controversial infrastructure projects, with MPs expected to vote on the final policy in the coming months.