Increasingly allergenic airborne pollen revealed in sediment of Lake Burley Griffin, Canberra

The incidence of allergy-related respiratory ailments in Australia is ranked amongst some of the highest in the world. Of interest is how European settlement and the introduction of numerous wind pollinated species from the Northern Hemisphere may have increased the impact on public health. Although anecdotally known as the hay fever capital of Australia, there is very little aerobiological data published for the city of Canberra [Davies, J. M. et al. (2015) ‘Trans-disciplinary Research in Synthesis of Grass Pollen Aerobiology and Its Importance for Respiratory Health in Australasia’, Science of the Total Environment, 534: 85–96]. Canberra, however, is a planned city, with the bulk of its expansion and construction occurring since the latter part of the 20th century. The well-documented development of Canberra provides a unique opportunity to assess the evolution of the allergenic environment in this region through the lens of palaeoenvironmental reconstruction. Sediments collected from Lake Burley Griffin were processed for their pollen content to assess how the allergenic load has changed since the founding of Canberra. The analysis reflected historical records of changing land uses and revealed an increasingly allergenic airborne pollen load over the past 90 years, coinciding with population increase and urban development, and underpinned by Canberra’s tree planting scheme. In addition, fire was examined in the record, with the charcoal fractions revealing a complex fire history. Peaks that correspond to the 2003 Canberra bushfire are small relative to other peaks in the profile