Hearts and Homes: The Potential of Conservation Laser Cleaning for Post-disaster Wellbeing and Waste Reduction

Introduction
The bushfires that ravaged the south east of Australia in 2019 have surfaced problems in commercially driven practices of clean-up and damage remediation. The current pathway, from insurance assessment and pay-out, to builder quotation, material purchase and project management, is driven by assumptions that damaged materials should be replaced rather than repaired or restored. In practice this has created a process that is slow, because so much has to be rebuilt from scratch; creates a massive burden of waste; and is emotionally alienating, as the remains of people’s personal heritage are revalued as waste and carted away.

The discipline of materials conservation is founded on the assumption that old and damaged materials can hold significance and value, and that care can preserve and enhance those values. In times of disaster, when so much is lost, there is strong potential to use materials conservation to help return a sense of control, continuity and connectedness to people and communities by preserving physical items from the time before the disaster. This is the mission of organisations such as Blue Shield, and of the many conservators and organisations who donate their time and skills in the aftermath of disasters.

Most of these efforts, however, are focused on items or collections of special significance. We would like to apply conservation techniques and approaches to the broader “personal heritage” of homes and possessions that are not in themselves precious, but that together provide a sense of place, and that embody and express the ambience of lives and families over time.

This paper discusses the potential of conservation laser cleaning techniques to assist recovery and remediation processes for disaster-affected homes and possessions.

Method
Nanosecond pulse lasers (which clean through heat related effects) and femtosecond pulse lasers (which can clean by breaking bonds directly – the so-called “cold ablation” effect) will be used to clean samples of materials affected by the 2019 bushfires. The effectiveness of the laser cleaning will be analysed using techniques including optical and electronic microscopy, and human sensory responses (vision, touch and smell).

Preliminary discussions will also be held with building industry representatives and people affected by the bushfires, to evaluate the perceived practicality and acceptability of laser cleaning for remediation of homes and possessions.

Implications and impact
In contrast to most commercial laser cleaning processes, conservation laser cleaning draws on heritage ideas of the value of retaining and repairing materials rather than discarding them, and of understanding the importance of those materials in preserving emotional connections to the past. It is therefore hoped that conservation laser cleaning can promote cleaning and repair rather than discard of materials, with beneficial effects on post-disaster emotional wellbeing and reduction in the amount of damaged material being sent to landfill.

Conclusions

This work will explore the potential of both nanosecond lasers (which clean through heat related effects) and femtosecond lasers (which can clean by breaking molecular bonds directly – the so-called “cold ablation” process) for removing bushfire related ash deposits, smells and charring from building materials, and will assess the practicality, cost-effectiveness and acceptability of lasers for remediating disaster affected homes and possessions.