New Delhi: A study by the University of Auckland, published in the Australian and New Zealand Journal of Public Health, highlights the association between higher population density and deteriorating air quality in Auckland, New Zealand's largest city.
The research, based on data from 2015-2017, revealed that respiratory hospitalizations and childhood asthma were more prevalent in densely populated areas. Air pollution, particularly nitrogen dioxide (NO2), was strongly linked to higher population density. According to the study, “housing intensification will likely increase ill health from air pollution unless steps are taken to reduce exposure to emissions from motor vehicles.”
Among various pollution sources such as motor vehicle traffic, domestic fires, and industry, motor vehicle emissions were identified as the most significant contributor to air pollution, especially in the city’s most crowded regions. The study underscored the necessity of implementing transport reforms to curb vehicle emissions as part of planning for increased urban density.
The research explored the connections between population density, air pollution levels, and associated health outcomes in Auckland, as reported by Xinhua News Agency. It found that higher population density correlated with elevated concentrations of nitrogen dioxide (NO2) and fine particulate matter (PM2.5). Health impacts related to NO2 exposure and respiratory hospitalizations due to PM2.5 exposure rose incrementally with urban density.
In a separate public health concern, New Zealand's health ministry launched a nationally coordinated response last November to address the early stages of a highly contagious whooping cough epidemic. Cases had risen steadily over weeks, reaching the threshold for a national epidemic. The ministry referred to the country’s last major pertussis outbreak in 2017, which persisted for several months to over a year.
According to the Institute of Environmental Science and Research, whooping cough cases began climbing in May, June, and July. Nicholas Jones, Public Health Director, warned that New Zealand might face similarly high levels of pertussis cases over the next year, citing a global surge likely linked to reduced infection rates during the COVID-19 pandemic.
Jones emphasized the heightened risk for severe illness in unvaccinated infants, those with delayed immunizations, and vulnerable groups such as Māori and Pacific communities. He stated, “Even in countries with high vaccination rates, epidemics still occur,” while stressing the importance of maternal immunization during pregnancy and timely vaccinations for infants to minimize severe cases.
“Even in countries with very high levels of immunization, epidemics still occur every few years, but the number of babies who get very sick is much lower when mothers have been vaccinated during pregnancy, and when people are vaccinated on time,” he added.