The World Health Organization has warned that hairdressers may be routinely exposed to cancer-causing chemicals. But the American Cancer Association says studies have not found a strong link between cancer and hair products and recommends more research. In 2011, a health agency of the U.S. Department of Labor5 found that some “hair smoothing” products may release unsafe levels of formaldehyde, which is toxic. Dr. Oluwakemi Osunderu has been doing her own research, _______________________________________.
世界卫生组织警告称，理发师由于工作的原因，可能会经常接触引发癌症的化学成分。不过，美国癌症协会称，这样的调查报告并没有揭示出癌症与护发用品之间的直接因果关系，并建议进行更多相关调研。
2011年，美国劳工部的卫生部门发现一些护发素可能会释放出有毒的甲醛，对人体不健康。Oluwakemi一直在进行调研，______________________________。
