Background Worldwide, 5000 billion cigarette butts, containing more than 4000 toxic chemicals, are estimated to be each year littered. If the deleterious health impacts of smoking are well known, the roles of cigarette butts require clarification. Indeed, this pollution could have repercussions on health and the environment. Objectives We aimed to review all main impacts of cigarette-butt pollution on human, animal, vegetal and environmental health. Methods All electronic databases (from 1948 to March 2020) were searched with a combination of keywords related to cigarette butts and to human, animal, vegetal or environmental health. Two independent reviewers selected studies of any design and in any language, using original data and investigating the associations between cigarette butts and human, animal, vegetal or environmental health. The selection was performed from abstracts and titles and pursued by reviewing and extracting data from the full text of potentially eligible studies. Results After a detailed screening of 98 entire studies, 63 studies were identified. In some studies, nicotine poisoning or occlusive syndrome were described in young children and domestic animals. Other studies showed also river, ocean or coastal pollution by metals, polycyclic aromatic hydrocarbons or nanoparticles with toxicities on animals and plants, impacting the entire food chain down to humans. A few studies highlighted toxicity on species resistant to traditional insecticides (malaria vectors) and indicated that even rats were avoiding areas polluted by cigarette butts. Finally, the majority of studies reported pollution on all continents, either in urban or coastal regions, while cigarettes butts are not quickly biodegradable. Conclusion Deleterious impacts of cigarette butts on human, animal, vegetal and environmental health are beginning to be described in the literature. The ubiquitous and growing nature of this pollution must raise concern among the civil societies and government in order to intensify the fight against smoking.

Abstract Background It has been suggested that the adverse effects of passive smoking on children could be avoided by breastfeeding, especially when they were breastfed longer than 4 months. However, those results have to be more consistent. On the other hand, it has already been shown that tobacco could pass through breast milk with adverse effects on child depending on components. Our aim was to study the link between passive smoking and breastfeeding on health issues of children exposed to passive smoking by their mother during the pregnancy. Methods We identified our variables on child’s health statements at 8 days and 9 months of life. Each child-smoking mother pair was included in the study. Univariate then multivariate logistic regressions were conducted to estimate first an adjusted odds-ratio of being sick at nine months according to the duration of breastfeeding, and then to estimate another adjusted odds-ratio of being breastfed for longer depending on whether the child was sick before nine months or not. Results Univariate analysis have shown a protective effect of a breastfeeding longer than 4 months (OR = 0.44, 95% CI [0.22; 0.90]), which disappeared in multivariate analysis after adjustment (aOR = 0.47, 95% CI [0.22; 1.01]). However, being healthy at nine months increased the probability to be breastfed at least 4 months (aOR = 2.85, 95% CI [1.31; 6.23]). Conclusion Breastfeeding’s effect seems to be insufficient on passive smoking’s adverse effects. Smoking cessation is still a priority when the mother smokes whether she breastfeeds or not.