Air quality is expected to deteriorate across much of mainland Portugal over the coming days as dust carried from North Africa moves through the atmosphere, with health authorities warning vulnerable groups to take extra precautions.

Portugal’s Directorate-General of Health (DGS) has issued a warning about the expected decline in air quality, particularly in central and southern parts of the country. The dust is being carried by an air mass originating from the deserts of North Africa and is expected to affect much of mainland Portugal.

The Portuguese Institute for Sea and Atmosphere (IPMA) has also forecast suspended dust on Friday and Saturday.

The DGS said the phenomenon is expected to increase concentrations of naturally occurring inhalable particles, particularly PM10, in the air. Exposure to elevated levels of these particles can affect health, with children, older people and those with existing medical conditions considered more vulnerable.

Health officials are advising people to avoid prolonged physical exertion and reduce outdoor activity while the dust remains in the atmosphere. Residents have also been urged to avoid exposure to tobacco smoke and other sources of irritation.

Children, elderly people and those suffering from chronic respiratory conditions, particularly asthma, are being advised to remain indoors whenever possible. People with cardiovascular disease are also considered at greater risk. The DGS recommends that vulnerable residents keep windows closed where possible during the episode.

People receiving treatment for chronic illnesses have been advised to continue taking their prescribed medication.

The air-quality warning comes as parts of Portugal also face a heightened risk of rural fires amid continuing hot weather.

Eleven municipalities in the districts of Bragança, Guarda, Castelo Branco and Coimbra are under the highest rural fire alert level on Friday, according to IPMA.

The weather agency has also issued yellow heat warnings for several districts, including Bragança, Viseu, Évora, Guarda, Faro, Vila Real, Setúbal, Santarém, Lisbon, Leiria, Beja, Castelo Branco, Coimbra and Portalegre. The warnings remain in place until 7pm on Saturday.

Temperatures are expected to ease slightly from the peak recorded on Thursday, particularly along coastal areas, but conditions will remain warm. Temperatures are forecast to stay above 20C in many areas, including regions south of the Tagus River.

The combination of suspended dust and high temperatures could create additional challenges for people with respiratory and cardiovascular conditions. Authorities are therefore urging vulnerable residents to limit outdoor activity and monitor their health while the dust episode continues.

The DGS has stressed that precautions should remain in place for as long as the poor air-quality conditions persist, particularly for people who are more sensitive to airborne particles.

New Zealand has authorised two psychiatrists to prescribe pharmaceutical-grade MDMA to patients with severe post-traumatic stress disorder (PTSD), making it only the second country after Australia to permit the drug for clinical treatment.

Wellington psychiatrist Dr Gary Wynn and Auckland psychiatrist Dr Tom Paterson received approval from New Zealand’s medicines regulator, Medsafe, following a regulatory process that lasted more than a year. The approvals allow MDMA to be used in controlled clinical settings as part of treatment for eligible patients.

Deputy Prime Minister David Seymour welcomed the decision, saying PTSD can have a devastating effect on people and remains difficult to treat. Seymour previously supported approval of psilocybin, the active compound in magic mushrooms, for severe depression.

PTSD can develop after people experience or face the threat of traumatic events, including combat, sexual assault and the sudden death of someone close to them. Symptoms can include intrusive memories, anxiety, sleep problems and emotional distress.

Treatment options remain limited in many countries. Two antidepressants are commonly approved for PTSD, but they can take several months to produce an effect and do not work equally well for every patient.

New Zealand’s decision is based partly on results from two international Phase 3 clinical trials conducted by the US-based Multidisciplinary Association for Psychedelic Studies (MAPS) and sponsored by its public benefit corporation, Lykos Therapeutics.

A 2021 trial found that 88% of participants with severe PTSD who received MDMA-assisted therapy experienced clinically significant improvement, while 67% no longer met the diagnostic criteria for PTSD.

A second trial, published in 2023, involved people with moderate-to-severe PTSD. Researchers reported that 71.2% of participants receiving MDMA-assisted therapy no longer met the diagnostic criteria by the end of the study.

The evidence has faced scrutiny in the United States. The US Food and Drug Administration rejected approval of the treatment in 2024, citing concerns about the available evidence for its safety and effectiveness.

US regulators also raised concerns about expectancy bias among participants who had previously used MDMA, which could have affected the reliability of the trial findings.

New Zealand has opted for a tightly controlled approach. The Ministry of Health said MDMA treatment would only be provided alongside psychotherapy in a clinical environment and would not involve take-home doses.

Patients must be at least 18 years old, and treatment must be administered by an authorised psychiatrist as part of a comprehensive care plan.

The approvals mark a significant step for psychedelic-assisted therapy in New Zealand while keeping MDMA use under close medical supervision.