Health & evidence Data centres
What the BMJ says about data centres and health
A leading medical journal has published an expert warning that data centres threaten people’s health and the environment — and that the harms are largely avoidable. Here is what it says, in plain English, and why it lands on the 96 MW data centre already approved next to Abbots Road.
First, what this is — and isn’t
The piece is an expert opinion in the BMJ’s “News & Views” section, published on 29 September 2026. It is written by Julie McNamara, federal energy policy director at the Union of Concerned Scientists. It is not new research, and it does not mention Abbots Langley or this scheme.
The article is global. The connection to our area is ours — so we keep the two clearly apart below: what the BMJ says, then what it means here.
What the article says
Writing in the BMJ, McNamara argues that the rush to build large, energy-hungry data centres for artificial intelligence is imposing “severe and largely avoidable harms” on communities — because “open loopholes and lack of accountability” let the costs fall on other people. The article names five pathways:
- Noise. Communities near data centres report “unrelenting noise”, which the article links to disrupted sleep, mental health and cognitive effects, a poorer quality of life — and a toll on local wildlife.
- Water. Data-centre water use is already “straining and degrading” local water systems, especially in water-stressed places. The article cites an estimate that global data-centre water consumption will more than double between 2023 and 2030, and notes that secrecy around facility water use makes the problem worse.
- Energy and fossil fuels. Individual hyperscale facilities now demand as much power as entire cities. Even when they connect to the grid, the article argues the sheer scale “threatens to stall clean energy transitions” and drive a spike in gas. For the UK, it cites the risk that the data-centre queue drives gas use equivalent to 20% of the UK’s projected total emissions in 2035.
- Diesel back-up generators. Common for backup power and sometimes numbering in the hundreds per site, these emit hazardous air pollutants and “can quickly become the largest local source of air pollution in a community”.
- On-site power plants. Some projects install their own generators to sidestep grid constraints — often gas — and the article describes cases of highly polluting turbines being trucked in to power new sites.
Its conclusion is that these harms are “not inevitable”: each facility has options for mitigation, “including scrapping specific projects altogether”. What is missing, it argues, is a coordinated regulatory response with real transparency, accountability and public participation.
Why it matters here
Every mechanism the article describes is already present at Abbots Road — on a scheme that has been approved, and not yet built:
- A 96 MW / 84,000 sqm data centre at Bedmond Road was approved on appeal in May 2025. The decision records emergency back-up generators and buildings up to 20 m tall with flues to a further 5 m — beside 900 homes at H9.
- Water. The district is classed as an area of serious water stress. Abbots Langley has been under a hosepipe ban since 17 July 2026, and drought was declared across Hertfordshire on 29 July 2026. The data centre’s own water demand has never been published.
- Cumulative impact. The plan adds the 900 homes, the data centre and further schemes around them, but there is no published assessment of the cluster together — for water, air, noise or grid capacity. The BMJ article is, in effect, a warning about exactly that gap.
The report sets out the local evidence in full, source by source: The Abbots Road Report →
Read it yourself
The BMJ opinion is free to read:
McNamara J. Data centres: Tech companies are putting health and the environment at risk by exploiting regulatory gaps. BMJ 2026;394:e100990. Published 29 September 2026.
Said fairly
This is a global, US-authored opinion piece. Its figures are the article’s own — we report them as its claims, not as our findings. The UK emissions comparison and the health mechanisms are the parts that travel; the link to Bedmond Road and Abbots Road is ours, made plainly. Where our own report states a local fact, it is footnoted to a public source.
Water, air, noise — and no cumulative assessment
The BMJ says the harms are avoidable and regulatory. That is why we ask for the data centre’s water and emissions to be published and conditioned, and for the cluster to be assessed as a whole.