More frequent and severe wildfires increase the temperature of the exposed land surface one year after the fire, according to an analysis of forest satellite data collected from 2003 to 2016. In recent decades, large wildfires have doubled or tripled their average size in eastern Spain, Canada, and western United States, as noted in the research published in Nature. The authors call for consideration of these effects on surface temperature when managing forests.

Canadian research analysing more than 863,000 births over almost a decade, including 806 surrogacy deliveries, concluded that the risk of severe maternal morbidity was 7.8% in gestational carriers, more than three times the risk of conception without assisted reproductive techniques and almost twice the risk in IVF pregnancies. The three most frequent complications were severe postpartum haemorrhage, severe pre-eclampsia and puerperal sepsis. The study is published in the Annals of Internal Medicine.

The Anthropocene began around 1952, according to a study based on geological records from 137 sites around the world, published in PNAS. The term ‘Anthropocene’ describes the period in Earth's history when human activities have drastically altered the planet; in March, an international scientific body dismissed it as an official geological epoch.

An international team of researchers has conducted a study in which they conclude that increased activity of the brain amygdala detected by magnetic resonance imaging is associated with an increased risk of developing symptoms of depression in pregnant women. According to the authors, the finding could be used to identify those who are more likely to suffer from postpartum depression. The results of the study, still in prepublication form and not yet peer-reviewed, will be presented at the ECNP (European College of Neuropsychopharmacology) conference.

A study has analyzed changes in the Earth's average global surface temperature over the past 485 million years and has discovered oscillations ranging from 11°C to 36°C, representing a variation of up to 25°C. The research concludes that temperatures during the Phanerozoic underwent more fluctuations than previously thought and shows a correlation between CO₂ and changes in Earth's temperature. The article, published in the journal Science, combines thousands of data points with a modeling method used for weather forecasting.

A review published in Science estimates that 2 % of rodent species are hyper-reservoirs, hosting and transmitting more than three pathogens to humans, including Lyme disease, Lassa fever and plague. In addition, the authors estimate that 10 % of rodents are reservoirs for one to three pathogens. These are especially so-called synanthropic species - animals that live close to humans and are able to adapt to these environments - such as black rats, Norway rats and house mice.

The number of people who suffer a stroke, die from it or live with a subsequent disability has risen sharply worldwide between 1990 and 2021, according to a study published in The Lancet Neurology. The contribution of high temperatures to ill health and premature death from stroke has increased by 72% since 1990. For the first time, the study reveals the high contribution (on par with smoking) of particulate air pollution to subarachnoid haemorrhage (fatal brain haemorrhage).

An international team of researchers has conducted a meta-analysis of 137 clinical trials involving nearly 90,000 people to assess the migraine efficacy of 17 available drugs. Their conclusions are that four drugs in the triptan group are more effective and cheaper than newer drugs such as gepants or lasmiditan, and that the efficacy of the latter is comparable to that of paracetamol and most anti-inflammatory drugs. The results are published in The BMJ.

An international team of researchers has analyzed various data sources and scientific literature and identified 3,601 chemical substances in human samples such as blood, urine or breast milk that are known to be in contact with food, for example, because they are used in packaging. According to the authors of the study, “this work shows that food contact materials are not completely safe, even if they comply with regulations, because they transfer known substances to food". The research is published in the Journal of Exposure Science and Environmental Epidemiology.

A new web-based tool analyzes major cities like Tokyo, Paris, Atlanta or Barcelona to see how close they are to the 15-minute city concept, where residents take less than those minutes to access essential services by foot, bike, or public transport. According to the study, published in Nature Cities, few cities fit this concept. The tool, which is freely accessible and uses data from 10,000 cities sourced from the open-source packages GeoPandas and OpenStreetMap, could be useful for developing action plans and estimating how viable it is to transform certain cities to follow this model.