The spatial and temporal variation of ambient air arsenic (As) in Auckland, New Zealand

Abstract

Ambient arsenic (As), often found as a component of particulate matter, is a significant threat to human health. The main source of As in the atmosphere is from anthropogenic activities such as industrial activity including copper smelters and combustion of coal containing high levels of arsenic. In New Zealand, the burning of treated wood is also an important sources of ambient As. As from both natural and anthropogenic sources is unsafe in any amount when inhaled. This study investigates the spatial and temporal variation of As in ambient air in Auckland. Measurements are made at 4 representative sample sites including Henderson, Takapuna, Papatoetoe and Penrose over a two month period. PM₁₀ air samples were collected every 24 hours from midday to midday and then analysed in the laboratory. The study focuses on the meteorological factors (wind speed, wind direction, rainfall, and temperature) which influence the spatial and temporal variation of ambient As in Auckland. In addition, the study examines evidence to determine the source of As at each study site. The results found that meteorological conditions have an influence on the spatial and temporal variation of ambient As in Auckland. However, the influence of rainfall is found weaker than other meteorological factors. Concentrations of ambient As in Auckland are found to be strongly related to domestic fires and CCA (Chromated Copper Arsenate) treated wood burning.