Background: Cardiovascular diseases (CVDs) are estimated to be the leading cause of global death. Air pollution is the biggest environmental threat to public health worldwide. It is considered a potentially modifiable environmental risk factor for CVDs because it can be prevented by adopting the right national and international policies. The present study was conducted to synthesize the results of existing studies on the burden of CVDs attributed to air pollution, namely prevalence, hospitalization, disability, mortality, and cost characteristics. Methods: A systematic search was performed in the Scopus, PubMed, and Web of Science databases to identify studies, without time limitations, up to June 13, 2023. Exclusion criteria included prenatal exposure, exposure to indoor air pollution, review studies, conferences, books, letters to editors, and animal and laboratory studies. The quality of the articles was evaluated based on the Agency for Healthcare Research and Quality Assessment Form, the Newcastle–Ottawa Scale, and Drummond Criteria using a self-established scale. The articles that achieved categories A and B were included in the study. Results: Of the 566 studies obtained, based on the inclusion/exclusion criteria, 92 studies were defined as eligible in the present systematic review. The results of these investigations supported that chronic exposure to various concentrations of air pollutants, increased the prevalence, hospitalization, disability, mortality, and costs of CVDs attributed to air pollution, even at relatively low levels. According to the results, the main pollutant investigated closely associated with hypertension was PM_2.5. Furthermore, the global DALY related to stroke during 2016–2019 has increased by 1.8 times and hospitalization related to CVDs in 2023 has increased by 8.5 times compared to 2014. Conclusion: Ambient air pollution is an underestimated but significant and modifiable contributor to CVDs burden and public health costs. This should not only be considered an environmental problem but also as an important risk factor for a significant increase in CVD cases and mortality. The findings of the systematic review highlighted the opportunity to apply more preventive measures in the public health sector to reduce the footprint of CVDs in human society.

Many studies have investigated the role of metals in various types of malignancies. Considering the wide range of studies conducted in this field and the achievement of different results, the presented systematic review was performed to obtain the results of investigations on the prevention and occurrence of various types of cancer associated with metal exposures. In this review, research was conducted in the three databases: Scopus, PubMed, and Web of Science without historical restrictions until May 31, 2024. Animal studies, books, review articles, conference papers, and letters to the editors were omitted. The special checklist of Joanna Briggs Institute (JBI) was used for the quality assessment of the articles. Finally, the findings were classified according to the effect of the metal as preventive or carcinogenic. The total number of retrieved articles was 4695, and 71 eligible results were used for further investigation. In most studies, the concentration of toxic metals such as lead (Pb), chromium (Cr (VI)), arsenic (As), cadmium (Cd), and nickel (Ni) in the biological and clinical samples of cancer patients was higher than that of healthy people. In addition, the presence of essential elements, such as selenium (Se), zinc (Zn), iron (Fe), and manganese (Mn) in tolerable low concentrations was revealed to have anti-cancer properties, while exposure to high concentrations has detrimental health effects. Metals have carcinogenic effects at high levels of exposure. Taking preventive measures, implementing timely screening, and reducing the emission of metal-associated pollutants can play an effective role in reducing cancer rates around the world.