For one, people turn red at different amounts of exposure.

首先，人的皮肤在不同程度的暴露下变红程度会有差别。

For those with very low genetic risk, no amount of exposure to environmental risk factors will lead them to develop schizophrenia; for those with very high risk, moderate additional risk might tip the balance.

对那些基因风险很低的人来说，不论多少环境因子都不会使他们患上精神分裂症；而对于患病风险非常高的人，中等的额外风险也可能会破坏这种平衡。