广播电视英语短句 第 88 课：偏头痛-3

The team then compared those records to weather conditions in the twenty-four hours before the hospital visits. 这个研究小组随后将这些数据与患者前来就诊前 24 小时的天气情况进行比对研究。

For every increase of five degrees Celsius in air temperature, the patients had a seven and one-half percent higher risk of migraine. 发现空气温度每升高 5 摄氏度 ，患者们患上偏头痛的风险就增加 7.5 ％。

Decreases in barometric pressure two to three days before the visit also appeared to trigger headaches, but to a lesser extent. 就诊前两到三天气压的降低也会成为诱发偏头痛的因素，但是影响程度较低。

The researchers found no evidence that air pollution influenced headaches. 研究人员尚未发现空气污染影响头痛的证据。

But they could not rule out the possibility of a smaller effect similar to that seen earlier for strokes. 但是与早期对中风研究中的发现一致，他们未能排除它有较小的影响的可能性。