Credits: ANI
Delhi NCR is already facing one of its toughest air-quality crises, and now another worry has emerged. Volcanic ash from Ethiopia’s Hayli Gubbi volcano has started drifting toward Indian skies. BBC reports that ash clouds from this rare eruption have reached Delhi, raising concerns about health risks in a city where clean air is already hard to come by due to rising pollution. As this volcanic ash moves closer, people fear it could worsen existing respiratory problems.
In Delhi, where the Air Quality Index (AQI) often falls in the “very poor” or “severe” range, even small increases in particulate matter can have serious health effects. Understanding what volcanic ash can do and taking the right precautions can help reduce its impact.
A volcano in northern Ethiopia erupted on Sunday for the first time in nearly 12,000 years. Winds blowing at 100–120 km/h carried ash plumes to several countries. The Hayli Gubbi volcano in Ethiopia’s Afar region erupted Sunday morning, and by late last night, ash clouds reached Delhi, which is already struggling with toxic air, causing some disruption to flights.
The ash plumes, rising thousands of feet into the atmosphere, first passed over Gujarat and then moved toward Rajasthan, Delhi, Haryana, and Punjab. According to the India Meteorological Department (IMD), the ash clouds are drifting toward China and are expected to clear from Indian skies by 7:30 pm.
Volcanic smog, also called “vog,” is generated whenever a volcano erupts. Global health bodies like the World Health Organization (WHO) and the US Centers for Disease Control and Prevention (CDC) have long studied its effects. Here’s what you need to know about how volcanic ash can impact health.
Volcanic ash is made of fine particles that can reach deep into the lungs. According to the US Geological Survey’s Impacts & Mitigation guidelines, inhaling these particles can lead to:
Even healthy individuals may experience shortness of breath or discomfort after heavy exposure. For those with pre-existing lung conditions, the effects can be much more serious.
IMD Director General M. Mohapatra stated that the plume is approaching Delhi NCR, but “any significant impact on ground-level pollution is unlikely” because most of the ash is high in the atmosphere. He added that the ash cloud may appear as a cloudy, hazy sky for a few hours as it moves eastwards.
Meteorologists and weather analysts have noted that the plume contains volcanic ash, sulphur dioxide, and tiny glass or rock particles. It is moving quickly, at around 100–200 km/h, according to reports.
Dr Aditya Nag, Assistant Professor, Department of Respiratory Medicine, NIIMS Medical College and Hospital, told us that even if most of the ash remains high in the sky, fine particles can settle on the ground and mix with Delhi’s already polluted air. Components like ash and sulphur dioxide can irritate the lungs, throat, and eyes.
Dr. Manav Manchanda, Director & Head – Respiratory, Critical Care & Sleep Medicine, Asian Hospital, told us that people most at risk include children, the elderly, and anyone with asthma or COPD. Volcanic ash can also pose environmental risks, such as reducing visibility or damaging engines.
“Abrasive particles in the volcanic ash can trigger bronchospasm in COPD and asthma patients, making their condition worse,” said Dr Aditya Nag.
Dr. Manav Manchanda, advise the same safety measures that apply during high pollution days:
Credit: Canva
While doctors across the world recommend ensuring that fluoride and other protective minerals make up your toothpaste, your body produces its very own amino acid that protect your entire dental cavity.
Arginine, an amino acid that is already present in saliva, can turn bacteria from damaging to protective in your mouth, a study has found.
When sugars from food are broken down by the many bacteria living in the mouth, acids are produced that gradually damage tooth enamel and lead to cavities. This is known as dental caries. Over time, this acid dissolves tooth enamel and causes cavities.
However, researchers at Aarhus University in Denmark have discovered that regular arginine treatment can significantly reduced the overall acidity levels in the mouth and prevent tooth decay.
Yumi Del Rey, microbiologist at Aarhus, said: ""Our results revealed differences in acidity of the biofilms, with the ones treated with arginine being significantly more protected against acidification caused by sugar metabolism."
Volunteers were then asked to instructed to dip the dentures in a sugar solution for 5 minutes, immediately followed by distilled water (as placebo) or arginine for 30 minutes, one on each side. This was to be repeated three times a day, with arginine treatment done on the same side each time.
Sebastian Schlafer, professor at the Department of Dentistry and Oral Health, explained: "The aim was to investigate the impact of arginine treatment on the acidity, type of bacteria, and the carbohydrate matrix of biofilms from patients with active caries."
After 4 days of this process, the biofilms were developed and the dentures were removed for detailed analysis. The researchers compared dental plaques grown on customized dentures on both sides of each participant's mouth using a special pH-sensitive dye called C-SNARF-4.
Additionally, the team also began to look into how arginine might be reducing acidity, by taking stock of which bacteria and sugars were present in each sample.
Biofilms treated with arginine showed lower levels of a sugar called fucose, while another sugar, galactose, was concentrated towards the outer surface of the biofilm, meaning both sugars were away from the tooth enamel.
After analyzing the DNA of bacteria present, the researchers found that arginine treatment significantly reduced a specific population of Streptococcus bacteria known to produce acid, while slightly increasing other bacterial strains that can metabolize arginine.
The scientists noted that while more research is needed into the arginine's effectiveness, the amino acid could be a promising new addition to oral hygiene products such as toothpaste or mouthwash.
Credits: Canva
Covid is returning, as the National Health Service, NHS UK warned that there has been a "bounce back" in respiratory viruses this winter, along with COVID too on the rise. While UK was already struggling with flu and norovirus on the rise, cases of COVID have also risen. The latest data from the UK Health and Security Agency (UKHSA) show that the number of patients in hospital beds with COVID per day has risen from 0.87 per 100,000, as compared with 0.77 per 100,000 the previous week.
NHS national medical director Professor Meghana Pandit said: “It’s clear that the worst is far from over for the NHS this winter, with hospitals again experiencing a rise in patients admitted with flu and other respiratory virus cases last week.”
Since the pandemic, there have been many variants of COVID. The virus has continued to evolve. Two new variants that caused the spike in cases in autumn were XFG, known as Stratus, and NB.1.1, known as Nimbus.
Stratus: It is a subvariant of Omicron variant and made of previous variants LF.7 and LP.8.1.2. It was first detected in a sample on January 27, 2025. Whereas, Nimbus was first detected on January 22, 2025. It also originated from the same omicron variant, which was the reason for spike in 2023.
The World Health Organization (WHO) describes stratus as a "variant under monitoring" after several countries in South East Asia reported a rise in new cases and hospitalizations with this variant being detected.
Among studies that focused on how symptoms appear together, fatigue stood out as the most consistently reported issue. It often occurred alone or alongside problems such as muscle and joint pain, brain fog, or breathlessness. Other symptom pairings that appeared frequently included loss of smell and taste, anxiety with depression, and various forms of musculoskeletal pain.
When researchers classified patients based on affected organ systems, respiratory problems were the most widespread, seen in about 47% of long COVID patients. Neurological symptoms followed at 31%, while gastrointestinal issues were reported by 28%. The authors stressed that these percentages reflect how often these clusters appeared within long COVID cases studied, not how common they are in the general population.
A smaller number of studies sorted patients by how severe their symptoms were, dividing them into mild, moderate, or severe categories using symptom scores, symptom counts, or quality-of-life measures. Three studies used clinical indicators for classification, including abnormal triglyceride levels and signs of restricted lung function on imaging.
As per the Centers for Disease Control and Prevention (CDC), here are the common COVID symptoms:
CDC says, look out for these signs:
Credits: Canva
While the National Capital is dealing with cold wave, the air quality also continues to worsen. In several parts of Delhi, the air quality reached severe category. The Indian Meteorological Department (IMD) also issued an Orange alert on Tuesday for cold wave. Dense fog also engulfed the city, with air pollution or the particulate matter being trapped in the air, turning the fog into smog.
The condition of air pollution in Delhi has remained concerning and the levels have spiked to 20 to 30 times above the safety levels recommended by the World Health Organization or the WHO. Many studies, including the official website of the Environmental Protection Agency (EPA), US notes that the small particulate matter found in the air pollution is directly linked to health problems. "Small particles less than 10 micrometers in diameter pose the greatest problems, because they can get deep into your lungs, and some may even get into your bloodstream," notes EPA.
The government is pursuing "smog eating" surfaces to deal with the pollution problem in Delhi. While it may sound like a strange thing in India, not to the world. In fact, in the Netherlands these were used to reduce local nitrogen oxide or the NO concentrations in the air, rather than greenhouse gas concentrations.
Smog usually contains a mixture of hydrocarbons, ozone, oxides of nitrogen and sulphur, and particulates. The pollution is caused by both photochemical reactions that involve sunlight, unburned hydrocarbons and nitrogen oxides, along with high concentrations of particulate matter, especially from vehicle exhaust, construction dust and biomass burning.
Environment Minister Manjinder Singh Sirsa announced "smog eating" surface as part of its pollution control plan, for which the government has also signed an MoU with IIT Madras.
The smog eating surfaces will be public surfaces coated with photocatalytic materials like titanium dioxide or TiO2 that is used to degrade pollutants.
The Deccan Herald quoted Dr Pradeep Singh, professor and head at the School of Advanced Chemical Sciences, Shoolini University, who explained: Photocatalytic materials are basically semiconductors. Substances like TiO2₂or zinc oxide are typically used as photocatalysts. When light falls on these semiconductor catalysts, electrons within them jump from one energy level to another, creating a hole. These photocatalytic holes and electrons subsequently form free radicals, which have strong oxidizing properties and can break down certain air pollutants with which they interact."
Smog contains mainly nitric oxide, nitrogen dioxide, sulphur dioxide, ozone, and particulate matter. When all of these interact with photocatalytic materials, gaseous pollutants convert into less harmful compounds, such as nitrogen oxides become nitrates or decompose into ions. This process is also known as pollutant mineralization.
Fun Fact: It was in 2017, when scientists in Italy developed a type of photocatalytic cement that could absorb pollutants and convert it into harmless salts. Palazzo Italia in Milan, opened in 2015, was the first building to use the cement.
As per Dr Ashish Moon, Head of the Civil Department at Smt Radhikatai Pandav College of Engineering, Nagpur, the impact depends on environmental conditions. He explained that titanium dioxide can locally reduce certain gaseous pollutants like nitrogen oxides under ideal conditions, rather than absorbing up to 50 percent of all harmful gases.
He also co-authored a paper in 2021, titled: Detailed Case Study on Smog Eating Tile, where he noted, "It is better to use it in liquid form than a powder. I have not come across any harmful interactions between TiO2 and particles or gases in the air." However, he also points out that how it will work in Delhi will depend on its weather conditions and atmosphere. "There should be enough UV light for the nanoparticles to activate," he said.
Will this arrangement really work? That is yet to see, although a 2023 Spanish study found that although this measure showed some improvement, but it only yielded a modest reduction in ambient NO2. We are yet to see how well it will work in Delhi and its neighboring city's pollution problem.
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