Lead
1 Unlike other toxic heavy metals,lead is relatively abundant throughout the world and,thus,has many potential pathways into the human body via inhalation and ingestion.
2 The potential for air pollution problems is greatest in the vicinity of sources and in densely populated areas.
非常感谢各位了，谢谢，谢谢
參考答案:铅
1 与其它重金属不同，铅在全世界分布相对丰富，因此，通过吸入和（食物）摄取进入人体有许多潜在途径。
2 在靠近铅矿的地区和人口密集地区，空气污染的潜在危险最为严重。
