Compared with single acid rain pollution, compound pollution made contents of Fe in spinach and romaine lettuce raised 1.48 and 15.89 times, but the contents of Mg decreased slightly.

• 与单一酸雨污染相比，复合污染使菠菜与生菜中铁的含量分别平均升高1．48和15．89倍，而镁的含量则略有降低。