Will climate change increase mutation and cancer risk?
Rising sea levels, extreme weather, and ecosystem disruption, are well known consequences of climate change, but emerging research also reveals a more intimate threat: climate change may be directly damaging our chromosomes and altering our genetic makeup. This hidden consequence could have profound implications for human health and evolution.
Over the last 12-months, 4 billion people, almost 50% of the global population, experienced at least 30 days of extreme heat (hotter than 90% of temperatures observed in their local area over the 1991-2020 period)[1]. Near-surface temperature for each year between 2025 and 2029 is predicted to be between 1.2°C and 1.9°C higher than the average over the years 1850-1900, with an 86% chance that at least one year will set a new record[2].
Climate Change and DNA Damage
When temperatures soar beyond normal ranges, our cells experience "thermal stress." This isn't just about feeling uncomfortable in the heat, it's about fundamental damage occurring at the molecular level. High temperatures trigger the excessive production and accumulation of reactive oxygen species (ROS), highly unstable molecules including hydrogen peroxide and superoxide anions that damage DNA, proteins and lipid membranes in a process known as oxidative stress.
Recent studies have shown that acute heat stress significantly increases DNA damage, particularly in tropical and subtropical regions where extreme temperatures are becoming more frequent and intense. DNA strands can break, genes can mutate, and the cellular machinery responsible for reading and repairing genetic information becomes overwhelmed[3].
The health consequences of climate-induced chromosomal stress are only beginning to be understood. Early research[4,5] suggests potential links to cancer development as chromosomal stress and DNA damage increase and promote genetic instability. Observational studies have already linked higher temperatures endured by pregnant mothers to Acute lymphoblastic lymphoma (ALL) developed during the childhood of their offspring.
Epigenetic Shifts Across Generations
Climate change also appears to influence how our genes are expressed through epigenetic mechanisms, the reversible switches that turn genes on and off. DNA methylation, one of the primary epigenetic processes, can be disrupted by climate-related stress, potentially affecting mental health, neurodevelopmental disorders and immune function. More worryingly, these DNA methylation changes can be passed down to future generations. Potentially a parent exposed to extreme climate conditions might unknowingly transmit altered gene expression patterns to their children, creating a cascade of effects that could persist for generations and maybe represent a new form of evolutionary pressure. Chromosome damage in reproductive cells has also long been recognised as a case of fertility issues and birth defects[6].
Pollution, Light Cycles, and Repair Mechanisms
Increased heat is only one aspect of climate change which may have an impact, the warming planet brings with it increased pollution, altered light cycles, and exposure to new environmental toxins. Each of these factors can also contribute to chromosomal stress and genetic instability. Air pollution particles can penetrate deep into our lungs and bloodstream, carrying mutagenic compounds directly to our cells7. Disrupted circadian rhythms from changing daylight patterns can interfere with the natural DNA repair processes that occur during sleep [8].
Genetic damage can also compromise immune function by increasing immune system dysfunction, potentially making populations more vulnerable to infectious diseases. This is a particularly troubling prospect as climate change also expands the range of disease vectors like mosquitoes and ticks [9].
Health Inequities and Public Risk
Some groups of the population may be at higher risk than others. Children, whose DNA repair mechanisms are still developing, may be particularly vulnerable. Outdoor workers, athletes, and people living in urban heat islands face greater exposure. Communities in tropical and subtropical regions, where extreme heat events are becoming more common face greater risk.
Socioeconomic factors may compound the risk. Those without access to air conditioning, quality healthcare, or the ability to avoid outdoor work during extreme heat face disproportionate chromosomal stress. Could climate change could exacerbate existing health inequalities at the genetic level?
What emerging research and technological developments offer potential strategies for monitoring and mitigating climate-induced genetic damage? Development of testing including real time monitoring of biomarkers such as 8-oxoguanine and γ-H2AX levels in saliva or blood may prove useful. Epigenetic age clocks which estimate how a body is ageing by analysing DNA methylation may also provide insight. Circulating DNA in the blood stream may allow assessment of systemic genetic damage.
Pharmacological Interventions could include antioxidant supplementation targeting specific ROS pathways (e.g., N-acetylcysteine for glutathione replenishment), heat shock protein inducers to enhance cellular stress response, DNA repair enhancers targeting specific pathways (e.g., PARP inhibitors, ATM kinase modulators). Gene therapy could potrntially be used to enhance DNA repair capacity in at-risk individuals and tools like dCas9-DNMT or dCas-TET might reverse climate induced epigenetic changes.
Population screening for climate-vulnerability polymorphisms may enable genetic counseling based on personalized risk assessment from genetic profiles. Genetic risk might also inform decision making on environmental modifications such as urban cooling strategies and development of climate controlled public space and extreme heat warning systems.
Understanding that climate change can damage our chromosomes adds new urgency to both climate action and public health planning. Early findings demand attention, but more research is needed to understand the full scope of climate-induced genetic damage and journals are currently calling for papers on this subject, not just for effects on human DNA but across flora and fauna[10,11].
As we work to mitigate climate change and adapt to its effects, we must also consider how to protect the health of the most affected populations. We remain alergly naive to the conseuqnences, but as Shakespeare wrote," For being green, there is great hope of help[12].
- How does the environment affect your DNA? | Royal Institution
- Genetic response to climatic change: insights from ancient DNA and phylochronology - PubMed
- https://climahealth.info/resource-library/effect-of-heat-stress-on-dna-damage-a-systematic-literature-review/
- https://www.sciencedirect.com/science/article/pii/S0006497124041776
- Lancet Planet Health. 2024 Jul;8(7):e506–e514.
- https://www.frontiersin.org/journals/epigenetics-and-epigenomics/articles/10.3389/freae.2024.1464276/full
- Environmental exposures – IARC
- Circadian rhythm disruption in cancer biology.
- Impact of recent and future climate change on vector-borne diseases.
- Call for Papers: Climate Change Genomics | Genome Biology
- Home page | Molecular Cytogenetics
- Shakespeare, Henry VI Part 2, Act 3 Scene 1
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