This is not to say all hair analysis is invalid.

这并不是说，所有毛发分析是无效的。

youdao

With hair analysis, physicians can tell if you have been affected by environmental pollution. They can also check your diet, diagnose some diseases, and monitor recovery from them.

通过毛发分析，内科医生可以判断你是否受到环境污染的影响，还可以核对食物对人的影响，诊断某些疾病，并监测疾病的复原情况。

youdao

Isotope analysis of her hair revealed that she spent the years before she died in America's western mountains, which helps detectives concentrate their search.

分析其头发中的同位素，显示了她在被害前曾在美国西部的山区生活过几年，这有助于警探集中调查。

youdao

Simpson's defense attempted to suggest Wednesday hair analysis is so vague it is like picking up a leaf and attempting to tell which tree it fell from.

CNN: June transcripts arranged by date.

Lawyers acting for Abdullah Ocalan say they sent strands of his hair for analysis after the prisoner complained of ill health and said he suspected he was being poisoned.

BBC: Abdullah Ocalan is serving a life sentence for treason

Coroner Dr Fiona Wilcox called his death "absolutely tragic" and called for analysis of hair samples to be considered for future drugs testing by cricket clubs.

BBC: Train death cricketer Tom Maynard was high on drugs