Table 4.

Summary of environmental and non-diet lifestyle factors associated with Hodgkin’s lymphoma

Potential risk factor	Summary of results
Smoking	Having ever smoked and being a current smoker associated with increased risk [38]
	Having ever smoked and current smoking associated [31]
	Current smoking associated [46]
	Years smoked, pack years and years since stopped smoking – no association [38]
	Age at initiation of smoking, duration, intensity, cumulative exposure, time since cessation – not associated [31]
	Having ever smoked, intensity, duration, age at initiation, years since cessation and childhood exposure – no association [46]
Childhood environmental factors	Numbers of younger siblings associated with protection [32]
	Being an older sibling potentially protective among younger adult patients [47]
	Number of older siblings – no association [32]
	Childhood household size no association[47]
	Bedroom sharing associated with reduced risk among younger adult patients [47]
	Persons per room, attendance at kindergarten, mother’s age at birth, personal and parental education levels – no association [32]
	Number of playmates – no association [47]