Dogs likely to bite on hot, sunny, smoggy days: Harvard study

The study was conducted to check whether “day-to-day rates of dogs biting humans is influenced by environmental factors”.

A Harvard study, recently conducted by a group of three people, on the relation between dog bites and climate change. The study found that the dog bite incidents “increased with increasing ozone, temperature, and UV irradiation, and decreased on rainy days and on holidays”.

As a part of the study, 69,525 reports of dogs biting humans which were sourced from public or ER records were analysed. (File)

The study's basis was that humans are more violent whenever the temperature and air pollution is high and was conducted to check whether “day-to-day rates of dogs biting humans is influenced by environmental factors”.

The study was conducted by Tanujit Dey, from Harvard Medical School, Antonella Zanobetti, from Harvard School of Public Health, and Clas Linnman, from Harvard Medical School.

The aim of the study was to “determine potential environmental contributions to the daily prevalence of dog bites in 8 US cities during the years 2009 to 2018 in relation to temperature, the air pollutants PM2.5 and ozone, while controlling for precipitation, UV irradiation, calendar, and seasonal factors”.

The study found that there was no effect of Particulate Matter 2.5 (PM2.5), which are the tine particles or droplets in the air.

The study concluded that, “Dogs, or the interactions between humans and dogs, are more hostile on hot, sunny, and smoggy days, indicating that the societal burden of extreme heat and air pollution also includes the costs of animal aggression.”

The study further stated, “Results for ozone and UV irradiation remained significant when analyzing winter and non-winter months separately. As ozone levels covary with temperature and UV irradiation, in sensitivity analyses, we further modeled the results excluding either UV or ozone and found that the estimates of other variables were not influenced by either of them.”

As a part of the study, 69,525 reports of dogs biting humans which were sourced from public or ER records were analysed.

“The impact of temperature and air pollutants were evaluated with a zero-inflated Poisson generalized additive model, while controlling for regional and calendar effects. Exposure–response curves were used to assess the association between outcome and major exposure variables,” the study said.

The study found out, “Dog bites represent 0.3% of all emergency department visit, and are a source of cosmetic disfigurement, trauma, finger amputation and occasional severe craniofacial injury and fatality.”

Things including dog-specific factors, victims' factors and dog-victim interactions were also analysed.