Table 1:

Environmental contexts of the risk environment

	Micro-environment	Macro-environment
Social	• Gendered power relations • Dynamics of assisted injection • Drug-related stigma in interactions with health care professionals • Violence and interpersonal conflicts • Local policing practices and crackdowns • Peer group dynamics and social norms	• Gendered inequities and gendered risk • Stigmatization and marginalization of PWUD • Racial or ethnic inequalities • Public discourses around public health, drug use, and welfare policies
Physical	• Drug use settings and characteristics (e.g. supervised injection facilities, public spaces) • Sex work locations • Homelessness and housing instability Neighbourhood deprivation, urban development, and spatial inequalities • Exposure to violence or trauma • Prisons and incarceration	• Drug trafficking and distribution routes • Geographic population shifts (e.g. neighbourhood and population mixing) • Population mobility and cross border migration
Economic	• Cost of living (e.g. drug-related costs, health treatments, housing costs) • Sex trade or sex work engagement • Lack of income generation and employment opportunities • Food insecurity	• Investment in health and social services infrastructure • Growth of informal economies • Investment in social housing • Criminal justice expenditures
Policy	• Access to low threshold and social housing • Abstinence-only drug policies and drug criminalization in healthcare settings • Coverage and availability of harm reduction services • Operating regulations at supervised injection facilities • Local policing practices and crackdowns	• National and international drug laws • Policies and laws for harm reduction programs and services • Policies and laws criminalizing sex work • Universal access to healthcare • Laws governing protection of human rights • Policies and laws governing pregnancy and drug use for women who use drugs