Past Sulfur Pollution Linked to Damage at Western Australia’s Ancient Rock Art Site

A new Western Australia government report suggests that much of the damage to the ancient rock art at Murujuga occurred during earlier periods of industrial pollution rather than as a result of current emissions. Murujuga, which includes the Burrup Peninsula and the Dampier Archipelago, contains an estimated one million to two million petroglyphs. The engravings were created by the Ngarda-Ngarli people over tens of thousands of years and portray animals, plants, rituals and other cultural practices. The site was added to the UNESCO World Heritage List in 2025. The findings come from the Murujuga Rock Art Monitoring Program, a three-year project involving Curtin University scientists and Aboriginal community members. Researchers combined measurements of rock conditions with laboratory experiments, air-quality data and analyses of rainfall chemistry. The team confirmed earlier observations that the weathered outer layer of rocks tends to have higher porosity—more tiny voids—at locations closer to industrial sites. Porosity was generally lower farther away. Researchers say atmospheric chemistry, rainfall acidity and laboratory testing point to historic sulfur dioxide pollution as a likely contributor. Sulfur dioxide can react with oxygen, water and other substances to produce sulfuric acid. According to the report’s findings, that acid can affect rock surfaces by dissolving manganese and iron oxides and leaving small holes. The researchers also believe microorganisms living on the rocks may have worked together with sulfur dioxide to produce some of the observed deterioration. However, the report did not find evidence that present-day industrial activity is accelerating the damage. Sulfur dioxide emissions declined sharply after the 1970s and 1980s, and researchers detected no acid rain during the observation period. Air quality also remained within the monitoring program’s interim environmental criteria. The study’s authors say the results indicate that industry and Murujuga’s rock art may coexist if emissions remain within established limits and air quality continues to be monitored. They caution that damage to the landscape is unlikely to have a single cause and plan to investigate how additional factors interact over time. The program’s four-year research phase is nearing completion. Its final year is intended to establish the foundation for longer-term monitoring and management, with traditional owners expected to remain central to conservation efforts.