Journalists

The way people respond to wildfire smoke varies depending on their level of education and only occurs once the smoke begins to pose a health risk. These are the main findings of a study based on geolocation data from 163,000 cell phones belonging to people exposed to air pollution during the 2018 wildfire season in California (United States). According to the authors, whose study is published in the journal PNAS, these gaps in awareness could pose an obstacle to interventions aimed at changing people’s behaviors. 

Exposure to neurotoxic metals poses the greatest risk to children’s brain development between the ages of six and nine months, according to an analysis of baby teeth from 489 children in Mexico. The study, published in Science Advances, identifies this window as a critical developmental stage during which exposure to these metals is linked to increased behavioural problems in childhood and smaller brain volume. The study includes boys and girls aged between 8 and 14 years old and uses their milk teeth as biomarkers to reconstruct concentrations of lead, zinc, copper, manganese, magnesium, lithium, strontium, barium and tin, from 20 weeks before birth to 40 weeks after.

Between 2010 and 2020, nearly 2.6 million sudden deaths were recorded in Europe. This finding shows an upward trend in sudden death–attributable mortality of 2.9 % per year, with a significantly greater increase in women—although the majority of sudden deaths occurred in men—and clear geographic differences, with higher increases observed in Eastern and Southern Europe. Spain showed the greatest increase among the countries analysed, with an average annual rise of 3.3 %. The results were based on mortality data from the World Health Organization (WHO), covering 26 European countries and more than 53 million deaths. The study, published in The Lancet Regional Health, did not investigate the underlying causes, but the authors hypothesise that differences in cardiovascular risk profiles, access to healthcare, and emergency response systems may contribute to the observed trends.

A study published in Science analyzed more than 100,000 human neocortical cells from weeks 13 to 23 of gestation, when cortical neurons are generated. The samples came from 26 donors, some with and others without Down syndrome. Using single-cell genomics, they observed how trisomy 21 disrupts the developmental sequence of various types of neurons, which could explain subsequent differences in cognition. A second study in the same journal, which examines the postnatal brains of children with Down syndrome, finds that many of these changes persist into childhood. The authors note that their study will not have short-term clinical applications, but they hope it can be used to develop specific drugs or create gene therapies. 

A study claims that 98% of the environmental claims made by meat and dairy companies constitute greenwashing—statements and promises of environmental action that are not backed by scientific evidence. The analysis is based on 1,233 claims published between 2021 and 2024 in sustainability reports and on websites (for example, “producing carbon-neutral dairy products by 2050 at the latest”) by 33 major companies, including Danone and Nestlé. “The meat and dairy industry may be misleading consumers and investors about whether and to what extent they are addressing environmental impacts, including climate change,” the authors write, whose study is published in PLoS Climate..

An international team led by the Institute of Evolutionary Biology (IBE), a joint center of the Spanish National Research Council (CSIC) and Pompeu Fabra University (UPF), has compiled the largest genetic database of Native American populations to date, including 128 new complete genomes. The research identified more than one million genetic variants not previously observed in other populations, revealing a unique genetic diversity. According to the authors, who published their work in Nature, “these results demonstrate the need to better represent these populations in genomics.”

The deliberate consumption of soil—known as geophagy—is a common practice among animals, either to supplement their diet or as a protective mechanism against intoxication and other digestive issues. For the first time, a research team with Spanish participation has documented this behaviour in Barbary macaques in Gibraltar, particularly during the summer, when tourist numbers peak. This has led the authors of the study, published in the journal Scientific Reports, to hypothesise that the purpose of geophagy is to mitigate the digestive discomfort caused by food provided by visitors.

NASA’s Curiosity rover has found more than 20 organic molecules in clay-rich rocks on Mars, according to a chemical analysis published in Nature Communications. Among them is a nitrogen-containing molecule with a structure similar to that of DNA precursors, according to a press release from the University of Florida. This organic matter may have been preserved for more than 3.5 billion years in Gale Crater, the article states.

A team from the Vall d'Hebron Institute of Oncology in Barcelona has published a study examining the impact of the exposome—changes in lifestyle and environmental factors—on early-onset colorectal cancer through epigenetic signatures. By analyzing methylation patterns in patients, they confirmed previously identified risk factors such as diet, educational level, and tobacco use. Additionally, they identified a significant association with picloram, a widely used herbicide. The results are published in Nature Medicine.

One of the best-known genetic risk factors for developing Parkinson’s disease is carrying variants of the GBA1 gene. A new study published in the journal Nature Medicine compared the microbiomes of 43 carriers of this gene who had not developed the disease with those of 271 Parkinson’s patients and 150 healthy individuals. The results showed, in addition to alterations in the microbiome in the patient group, that 25% of the microbiome of carriers of this gene exhibited alterations, representing an intermediate profile between the other two groups. The results were validated using independent cohorts from the United Kingdom, South Korea, and Turkey. According to the authors, “alterations in the gut microbiome can identify individuals with both genetic and non-genetic risk in the general population who may be progressing toward Parkinson’s disease.”