I hear there's new research on the hair color/cancer issue. Has a connection been established?

The latest word on this continuing concern comes from the International Agency for Research on Cancer (IARC), which has concluded that working regularly with hair dyes in hair salons and barbershops probably increases the risk of cancer and that long term employment in these establishments is "probably carcinogenic to humans."

However, the IARC, a World Health Organization panel, reported that there is not enough evidence to conclude that occasional personal use of hair coloring raises the risk of cancer.

This new report, published in the April, 2008, issue of Lancet Oncology, is the first scientific word on the subject since 2005, when Spanish researchers reported that their review of 79 studies from 11 countries yielded no strong evidence of a link between hair dye and cancer risk. The only connection the Spanish team observed was the possibility of a slight increase in the risks of leukemia and multiple myeloma, but they concluded that the causal effect was too weak to be a major concern.

Earlier, researchers at Yale University found that long-term use of dark hair dye by women who began coloring their hair before 1980 may increase the risk of non-Hodgkin's lymphoma. No such risk was seen among women who began dyeing their hair after 1980. Here, the difference may be due to the elimination of coal-tar-derived ingredients used in the older products that are known carcinogens. The Yale study was published in the Jan. 15, 2004, issue of the American Journal of Epidemiology.

In general, I discourage use of hair dyes containing artificial coloring agents, which to my mind are as suspect in cosmetic products as they are in food. Hair dyes applied to the head are absorbed through the scalp, where there's a very rich blood supply that may carry them throughout the body. I'm sure that the new IARC report won't be the last word on this subject. I'll keep you posted on developments.

我聽說了關于染發致癌的新研究。這兩者間有關系嗎？

人們對于染發致癌持續關注，最新的說法來源于國際癌癥研究機構，機構推斷在理發沙龍和理發店工作、定期接觸染發劑，將會增加得癌癥的幾率，在這些地方長期受雇會對人體產生致癌物質。

然而，國家癌癥研究機構，作為世界衛生組織的代表，報道說并沒有足夠的證據說明偶然使用染發劑會有致癌風險。

此最新報道出版于08年4月的《柳葉刀—腫瘤學》。這是自2005年來，西班牙研究者重新研究了11個國家的79項調查并得出沒有足夠的證據支持染發劑和致癌風險的關系之后，第一次有科學上的報道。

早些年的時候，耶魯大學的研究者發現，在1980年前開始使用染發劑的女性長期使用黑色染發劑，也許會增加得非霍金奇淋巴瘤的幾率。在1980年后染發的 女性中沒有看到如此癥狀。也許原因歸于舊時產品中的衍生的煤焦油元素，它是一種致癌物質。耶魯大學的研究發表于2004年1月15日的《美國流行病學雜 志》。

總體來說，我不贊成使用帶有人工色素染劑的染發劑，對于我來說，對化妝用品的不可信就像對食物中一樣。用于頭部的染發 劑被頭皮吸收，頭皮處有非常豐富的血液供給組織，也許將會把他們傳送到全身上下。我確信國家癌癥研究機構的最新報道不會是對這一問題的最終說法。我會為你 們提供這方面的最新消息。