Sustainability Implications of Single-use Products and Their Alternatives
Bioplastics are an often-touted alternative to single-use plastics. To compare the environmental impacts of these product's life cycle, a life cycle assessment (LCA) may be employed. However, there are gaps in the real-world usage and disposal behavior data available and how it is modeled. This work seeks to address gaps in real-world behavior data via surveys, waste audits, shadowing and direct observation; develop an LCA that incorporates real-world primary data; and add to the characterization factors available in LCA to develop robust LCAs of polylactic acid (PLA), which is a type of bioplastic. The work contained herein is written from a United States (US) perspective with its solid waste infrastructure in mind. The aim is to consider how human behavior affects the environmental impacts of single-use products and its alternatives when doing comparative LCA assessments. The waste audit was conducted to determine human behavior outcomes at the point of waste disposal. The findings reveal that individuals likely act on what they know when disposing of PETE but do not know or do not act on what they know when disposing of PLA, PP, and PS cups. The survey was distributed to learn about single-use product usage, possible reuse of single-use products, and waste-management practices during the COVID-19 pandemic in the US. Overall, respondents expressed a concern over single-use products and a preference for reuse of single-use products. A comparative cradle-to-grave LCA that included real-world behavior outcomes at point of reuse was conducted. The environmental impacts of using disposable acrylic speculums versus using reusable stainless-steel speculums were compared. Overall, no speculum system outperforms the other consistently across all TRACI impact categories, however, depending on the overall environmental objectives of a clinic one may be preferable to the other. Lastly, an effect factor (EF) specific to PLA microplastics (MPs) in the freshwater ecotoxicity impact category was developed. The EF is comprised of 9 ecotoxicological data points that represent 5 species and 3 tropic levels. The calculated EF is 164.24 (11.867-2273.25 CI) potentially affected fraction (PAF) m^3/kg at the midpoint level, and 4.106 potentially disappeared fraction (PDF) m^3/kg at the endpoint level. These findings are comparable to what previous researchers have calculated for other polymer types.The real-world human behavior data collected, and the EF factors developed in this study can be used in future comparative LCAs to contrast PLA with other polymer types to reduce the possibility of miscounting the overall environmental effects and avoid making off target product recommendations.