By Stephen Beech via SWNS
High pollen levels could hamper Olympic athletes as they go for gold in Paris, warns new research.
And the problem will be even worse if temperatures soar, say climate scientists.
The opening ceremony of the 33rd Olympics is due to take place in the French capital on Friday (July 26).
But high levels of the respiratory irritant ozone and grass pollen are likely during the two-week sporting extravaganza, suggests an analysis of historic air quality monitoring data for the city and surrounding area during previous summers.
Experts say that athletes can be affected by environmental factors, despite generally being in peak physical condition.
They warned that breathing in air pollution during exercise may pose health risks, depending on exposure levels and underlying long-term conditions- with endurance athletes particularly susceptible to allergic symptoms.
To try and estimate the potential impact of background air quality on athletes – and spectators – during the Games, researchers reviewed historic hourly data between July and September, for air pollutants (2020-23) and pollen (2015-22).
The figures were collected from 50 permanent automatic monitoring stations of the Airparif network for the Paris region, and from sensors in the Aerobiological Surveillance Network (RNSA).
The researchers focused on background levels of ozone (O3), nitrogen dioxide (NO2), and fine particulate matter (PM2.5).
The World Health Organisation (WHO) recommends air quality thresholds (AQTs) not to be exceeded for more than three to four days a year of 15 µg/m3 per 24 hours for PM2.5, 25µg/ m3 per 24 hours for NO2, and 100µg/m3 per 8 hours for O3.
The researchers calculated that the maximum daily average PM2.5 between July and September was 11µg/m3 at traffic stations, which is below the WHO-recommended daily AQT.
Daily average NO2 levels ranged from 5 µg/m3 in rural areas to 17 µg/m3 in urban areas.
But near traffic monitoring stations, the figure rose to 40 µg/m3 which exceeds the WHO recommended AQT.
Both peaked around 8 am and 8 pm local time. The ambient O3 level exceeded the WHO recommended AQT on 20 days/month and peaked at 4 pm local time, according to the findings published in the British Journal of Sports Medicine.
Doctors say ozone inhalation can cause airway inflammation, potentially resulting in airway constriction, cough, and shortness of breath.
Study author Dr. Valerie Bougault, of Côte d’Azur University, said that from their peak in June, pollen levels fall until September while between July and September, the general pollen level is three times lower than it is in Spring.
A total of 19 different pollen types were identified during the summer months, but nettles and grass pollen represented more than 92% of the total. Their allergic sensitivity is low, except for grass pollen, which is highly allergenic.
Dr. Bougault said: “Despite the lack of evidence towards an additive effect of ozone and PM2.5 on the association between pollutants and mortality, larger effects of air pollutants have been observed when the temperatures are warmer.
“Acclimatisation studies in healthy volunteers at very high ozone concentrations suggested that the first few days of exposure caused the worst respiratory symptoms and lung function decline, with at least three days of adaptation required, possibly longer for high responders.
“There is also evidence that people accustomed to ozone or traffic-related air pollution may experience reduced health or performance effects from acute exposure.”
She added: “In general, our data suggest that the concentrations of PM2.5 observed may have a limited impact on healthy people who will be in Paris for a short period during the Olympic and Paralympic Games, but may have a greater impact on certain vulnerable groups, such as people with chronic diseases, children and the elderly, and in particular those who are highly sensitive to pollutants.”
