Methodology
Methodology
References
Every assessment and claim in the Lifecycle methodology is grounded in peer-reviewed research, authoritative health organizations, and scientific consensus. The sources below are organized by topic.
Global Disease Burden & Environmental Health
- Global burden and strength of evidence for 88 risk factors in 204 countries and 811 subnational locations, 1990–2021 Global Burden of Disease Study 2021 · The Lancet, 2024
- Global Burden of Disease Study — environmental risk factors and health impact assessment World Health Organization (WHO), Global Health Observatory
- State of Global Air 2024 Report Air quality and health impact assessment
Air Pollution & Particulate Matter (PM2.5)
Microplastics
- Microplastics in Body: Polluted Tiny Plastic Fragments Stanford Medicine Insights, 2025
- Microplastics are everywhere — we need to understand how they affect human health Nature Medicine, 2024
- Potential Health Impact of Microplastics ACS Environmental Health, 2024
- Microplastics Everywhere Harvard Medicine Magazine
- Impact of Microplastics on Human Health MDPI Environmental Health Journal, 2024
Lead Exposure
PFAS (“Forever Chemicals”)
Endocrine-Disrupting Chemicals
- 9 Ways to Avoid Hormone-Disrupting Chemicals Natural Resources Defense Council (NRDC)
- The impact of perfumes and cosmetic products on human health: a narrative review Frontiers in Toxicology, 2025
- Synthetic Endocrine Disruptors in Fragranced Products MDPI Journal, 2024
- What are phthalates? Environmental Working Group (EWG), 2024
- What Are “Hormone-Disrupting Chemicals”? Cleveland Clinic
Flame Retardants
Livestock & Agricultural Emissions
- Accelerating climate solutions in agriculture: why reducing methane from livestock is an urgent opportunity Clean Air Task Force, 2024
- Animal Agriculture Leads U.S. Methane Emissions — 36% of U.S. methane from animal agriculture EPA Report, 2024
- Climate-Warming Methane Emissions from the World’s Biggest Livestock Companies Inside Climate News, 2025
Food Waste
- Food loss and waste account for 8–10% of annual global greenhouse gas emissions UNFCCC
- Food waste makes up “half” of global food system emissions Carbon Brief
- Food Waste and its Links to Greenhouse Gases and Climate Change USDA
- Food waste is responsible for 6% of global greenhouse gas emissions Our World in Data
Electronics & E-Waste
Plastic Pollution
Ultra-Processed Foods
- Ultra-processed food exposure and adverse health outcomes: umbrella review of epidemiological meta-analyses BMJ, 2024
- Are Ultraprocessed Foods Bad for Your Health? Yale Medicine
- What doctors wish patients knew about ultraprocessed foods American Medical Association (AMA)
- Ultra-processed foods linked to increased cancer risk, diabetes, and heart disease World Cancer Research Fund
- Spotlight on UPFs: NIH explores link between ultra-processed foods and heart disease NIH / NHLBI, 2025
Lifecycle Assessment Methodology
- How Bad Are Bananas? The Carbon Footprint of Everything Mike Berners-Lee — order-of-magnitude assessment framework that inspired our methodology
- ISO 14040 / 14044 International standards for lifecycle assessment (LCA)
- Ecoinvent Database Lifecycle inventory data for products and processes
- GaBi Database Environmental product lifecycle data
Standards, Certifications & Databases
- Intergovernmental Panel on Climate Change (IPCC) Global warming potential (GWP) calculations and climate science
- U.S. Environmental Protection Agency (EPA) Greenhouse gas equivalencies, environmental standards, and health guidance
- Centers for Disease Control and Prevention (CDC) Health impact data, exposure guidelines, and disease burden assessments