We have many other styles
Heterogeneous findings may be the product of cross-sectional designs with modest-to-moderate sample sizes, between-study variability in participant attributes (e.g., varying age ranges, smoking histories, sex ratios, or other sociodemographic characteristics), and/or methodological differences in MRI acquisition or data analysis parameters (e.g., smoothing, registration techniques, or normalization templates)
It can increase your risk for heart disease, vessel damage, blood clots, and heart attacks
They have worried that if e-cigarettes are regulated too heavily, or become too expensive because of the cost of regulatory compliance, the public could miss out on a device that might save lives