Despite the relatively benign material composition of construction and demolition waste (CDW), its mismanagement can result in considerable harm to human health, not only for the 200 million workers in the sector but also for those who live and work in proximity to construction and demolition activities. The population and workforce in low- and middle-income countries (LIMICs) is most at risk, and therefore we have focussed the attention of a systematic review of evidence that associates CDW with negative health and safety outcomes in those countries. We used PRISMA adapted guidelines to review more than 3,000 publications, narrowed to 49 key sources that provide data on hazard generation, exposure and/or risk. Subsequently, hazard-pathway-receptor scenarios/combinations were formulated, enabling indicative ranking and comparison of the relative harm caused to different groups. Though the evidential basis is sparse, there is a strong indication that the combustible fraction of CDW is mismanaged and disposed of by open burning in many LIMICs, including increasing quantities of plastics used in the sector. It is likely that the off-cuts/residues of these materials will be burned; the high chlorides-content PVC represents a serious risk when combusted in open, uncontrolled fires due to the release of dioxins and related substances. A long-standing and well-known hazard, asbestos continues to represent a threat to construction and demolition workers throughout the world. Despite being banned in most countries, exposure to asbestos particles is thought to claim the lives of a quarter of a million people every year. Though much of this risk is concentrated in high income countries where it has been used over more than half century, it is anticipated that more than half of all deaths from asbestos in the coming decades will take place in India where many asbestos products are still on the market, without any sign of prohibition. Overall highest comparatively risks are concentrated in LIMICs where the majority of workers are informal and highly vulnerable to hazard exposure. Combined with the sheer quantities of CDW, the risks can anticipated to persist – urgent attention to risk mitigation and control is needed.