What are the cons of sushi?

Could you elaborate on some of the drawbacks of consuming sushi? Are there any potential health risks or concerns that one should be aware of before indulging in this popular dish? Are there any specific ingredients or preparation methods that may pose a hazard, especially for those with certain dietary restrictions or allergies? Additionally, what about the environmental impact of sushi production and consumption - are there any negative consequences we should consider when making our culinary choices?