What is the disadvantage of GMO?

Could you please elaborate on the disadvantages of Genetically Modified Organisms (GMOs)? I'm particularly interested in understanding the potential health risks associated with consuming GMO-derived foods. Are there any long-term effects that have been observed in humans or animals? Also, I'm curious about the environmental impact of GMO crops. Do they pose a threat to biodiversity or could they lead to the emergence of new pests and diseases? Lastly, could you discuss any ethical concerns surrounding the use of GMOs? Thank you for your insights.