The World Health Organization (WHO) says air pollution causes the death of seven million people a year and accounts for a third of fatalities from stroke, lung cancer and heart disease, with more than 90% of children breathing toxic air every day.

参考翻译：世界卫生组织称空气污染每年导致700万人死亡，这一死亡人数占中风、肺癌和心脏病致死人数的三分之一，并且90%以上的儿童每天都在吸入有毒的空气。

Account for（account for这里译者理解成“占比”）的主语是否应该是air pollution？但从参考翻译中看出其主语为the death of seven million people，这里是因为and后面省略了重复部分（the death of seven million people）吗？是否并列句里只要成分相同就可以省略，不管它们是否同时做主语或宾语？

如果account for的主语是air pollution，这里的account for可以解释为“导致，解释…发生的原因”。前半句译为：世界卫生组织称空气污染每年导致700万人死亡，三分之一的中风、肺癌和心脏病致死事件都由空气污染引起。

不知道我的理解是否正确，还请老师帮忙解答。

以下是剑桥词典查到的解释，因无法截图，就直接复制了：

account for sth

— phrasal verb with account UK  /əˈkaʊnt/ US  verb [ T ]

to form part of a total:

High-tech companies account for 32% of the total value of the payrolls in the area.

to explain the reason for something or the cause of something:

Rural Americans are often older than those in other parts of America and that may account for the slower adoption rates for internet access.