**Core Concept**
The World Health Organization (WHO) has identified 10 chemicals of major public health concern that are hazardous to human health and the environment. These chemicals are the focus of international efforts to reduce their production, use, and release into the environment.

**Why the Correct Answer is Right**
Radium is a radioactive metal that poses significant health risks, particularly through radiation exposure. However, it is not among the 10 chemicals of major public health concern identified by WHO. The correct list includes chemicals such as Arsenic, Asbestos, and Dioxin, which have been linked to various types of cancer, respiratory diseases, and other serious health problems. Radium, while hazardous, is not a member of this specific group of chemicals.

**Why Each Wrong Option is Incorrect**
**Option A:** Arsenic is a toxic metal that can cause skin lesions, cancer, and other health problems. It is indeed one of the 10 chemicals of major public health concern identified by WHO.
**Option B:** Asbestos is a group of minerals that can cause respiratory diseases, including lung cancer and mesothelioma. It is also on the WHO's list of major public health concern chemicals.
**Option C:** Dioxin is a highly toxic and carcinogenic chemical that can cause a range of health problems, including cancer and reproductive issues. It is one of the 10 chemicals of major public health concern identified by WHO.

**Clinical Pearl / High-Yield Fact**
The WHO's list of 10 chemicals of major public health concern highlights the need for international cooperation to reduce the production and release of these hazardous substances. Understanding the risks associated with these chemicals is crucial for public health professionals, policymakers, and individuals working to promote environmental health.

**✓ Correct Answer: D. Radium**