Healthcare is at a crossroads. Ever increasing demand from an ageing population combined with escalating costs of care means the system will become unsustainable. Building a National Health Service that is fit for the future is one of the government’s key missions to deliver on over the course of this parliament and beyond. The transition away from a reactive model of care to one that prioritises prevention, is considered by government as one of the three big shifts that will future proof our health service and deliver better outcomes for patients.

• Underlying traits of a preventative model include averting illnesses before they happen and the earlier identification and management of chronic illness.
• Such a transition can only occur where consideration is given not just to genes but also the environment as a determinant of health.
• This places an importance on the availability of environmental data both to public health practitioners from an operational perspective and those who researching new methods of prevention.

Genes and the environment as determinants of health
Health outcomes are not solely determined by our genes but also by environmental factors. Non-communicable diseases are often caused by the interaction between genes and lifetime exposure to harm. Harmful exposure could be naturally occurring, such as radon gas, or result from human development, such as air pollution from burning fossil fuels, or through individual choice, such as a sedentary lifestyle, or through deprivation, such as mould in poor quality housing. An individual’s risk of developing a disease has two components: the baseline risk determined by their genes and additional risk caused by lifetime exposure to harms. The greater the exposure to those harms, the higher the risk of developing disease. This has been coined the “exposome”.

Disease prevention
Disease prevention falls into two categories; primary prevention which aims to stop problems developing in the first place by taking actions at population level that eliminate or reduce exposure to harm, and secondary prevention which aims for early detection so that intervention can be employed to stop or delay deterioration in health.

Methods of primary prevention might include the introduction of traffic calming measures in urban areas where there is poor air quality, to reduce pollution levels. For instance, in London, congestion pricing and ultra-low-emission zones have been introduced to reduce the prevalence of harmful pollutants such as nitrogen dioxide and other particulate matter in the air, which has had health benefits for 5 million people living in outer London.

Active transportation, or infrastructure that encourages walking and cycling, is also an example of disease prevention. Research from The University of Manchester, considers pollution levels around schools, the impact of this on the health of children, and the importance of a community centred approach to active travel policies, so that commuters can use active travel methods to complete their journeys. By encouraging the take up of active travel, individuals will get the health benefit of more physical activity but also reduces air pollution from vehicles.

Access to urban green spaces. Parks, gardens, and green corridors within cities provide residents with spaces for recreation and relaxation and are known to be beneficial for good mental health.

The dominant method of secondary prevention is use of screening to identify those that have high exposure to harms such as air pollution or long-term exposure to irritants like those from smoking. Such screening, pioneered by The University of Manchester, is now transforming outcomes for patients with lung cancer, after researchers took screenings into communities in a bid to increase earlier detection and improve uptake in those most at risk. This improved detection three-fold compared to the international average.

Challenges with prevention
There are several challenges associated with prevention relating to harms caused by environmental factors.

Identification of needs
The genetic revolution has given us one half of the story through things such as the biobank sequencing. However, we need to better understand how genotypes interact with the environment. With progress and innovations being made in this area, this should become more plausible than in the past.

Competing priorities
In a system with constrained resources the key question is “where do you get the most improvement for your investment?” Answering this requires taking a holistic view of health and environment and considering the impact of policies that would traditionally sit outside of the health remit, like transport, on health outcomes. For example, if we want to reduce demand in doctors’ surgeries what impact would we have by changing traffic policies to reduce air pollution in areas with existing high levels of health deprivation.

Data fragmentation
Healthcare data, genetic sequencing data and environmental data exist in silos. We need to be able to link them quickly and easily to create a high-resolution picture of exposure and risk.

The role of the Digital Solutions Hub (DSH)
One of the key resources available for understanding the impact of the environment on health and prevention is the Digital Solutions Hub (DSH), which offers environmental data that can be linked to population-level health data. By leveraging the DSH, researchers can explore issues related to gene-environment interactions and their impact on health. This approach allows for a more nuanced understanding of how environmental context influences genetic predispositions to certain diseases. For example, air pollution is a known factor that affects lung health. By examining the interaction between genetic susceptibility and exposure to air pollution, we can gain a clearer picture of the underlying mechanisms that contribute to respiratory diseases.

To quantify the impact of lifetime exposure to environmental hazards, it is essential to undertake comprehensive population health studies that link health records, genetic data, and environmental exposures. These studies can provide valuable insights into the correlation and causation of environmental factors on health outcomes. The drive towards genomic health service announced in the NHS 10 year plan and the recently announced National Health Research Data Service if linked to the DSH would provide a unique capability to develop new insights into the environment-health-genome interaction.

The DSH will also be useful for those managing service delivery for the NHS, as healthcare providers will be able to monitor, in real-time, local air pollution levels on the Hub. In doing so, NHS trusts will be able to more effectively respond to incidences of poor air quality by ensuring more staff are put on shift for expected increases in admittance to A&E for respiratory problems and become more resilient to shocks and triggers.

Policy Recommendations
The government should invest in large scale population comprehensive health studies that link genetic data, health records, and environmental exposures. This will provide a robust evidence base for understanding gene-environment interactions. Policymakers should utilise resources like the Digital Solutions Hub to integrate and analyse data from multiple sources. This will enable more precise identification of environmental risk factors and their impact on health outcomes. Researchers and health practitioners should use the Unique Property Reference Number service to provide the link between an individual’s geolocation over time and their environmental exposure to begin to deduce the exposome. Policymakers should develop place-based prevention policies and programmes that enable the ‘shift left’ to prevention and are delivered digitally using linked environment-health-genomic data.

The relationship between genes, environment, and health is complex and multifaceted. By leveraging digital health data, investing in comprehensive studies, and implementing thoughtful prevention policies, we can create healthier communities and reduce the burden of disease. Policymakers must take a proactive approach to address environmental hazards and their impact on public health, ultimately leading to a healthier and more sustainable future for all. The DSH provides access to a rich data set that can be linked to population level health data to explore issues of correlation and causation around environment and health.