Where, and Why, Allergies Are Worst

Helen Lock starts this tale of seasonal allergy suffering with a particularly debilitating, even tragic, episode in Melbourne, Australia:

In 2016, Melbourne experienced a rare and extreme case of “thunderstorm asthma” that led to ten deaths and 8,500 people being admitted to hospital in one day. Ambulance dispatchers struggled to cope with 1,900 calls in the space of five hours, and one hospital ran out of Ventolin asthma inhalers. The storm had caused grass pollen to burst in the air, creating tiny particles that caused serious breathing problems when inhaled.

While allergy seasons like that have led some academics to declare the city the worst in the world for allergies, other cities have their own unique concoction of natural and human-designed factors that lead to seasonal suffering.

Meanwhile, in London, landscaping practices have led to an abundance of tree pollen, aggravating hay fever, according to a horticultural expert. Landscapers in the UK capital – and around the world – plant predominantly male trees because they are less messy than female trees, which shed seeds, fruits or pods, says Thomas Leo Ogren, creator of the Ogren Plant Allergy Scale. “The problem is that while these [male] trees and plants are litter-free, they all produce abundant allergenic pollen.”

Lock's tours Canberra, Tokyo, most of England, and the United States. Stateside, the Allergy and Asthma Foundation of America releases a report [pdf] that ranks cities by pollen counts. "In 2018, McAllen in Texas, Louisville in Kentucky and Jackson in Mississippi made the top of three of the organisation’s 'most challenging places to live with spring allergies' list," according to Lock.