Heavy Metal Toxicity & Sunburn Risk Sunburn is usually blamed on excessive sun exposure or lack of sunscreen — but emerging research suggests there may be another hidden factor influencing how our skin reacts to the sun : environmental toxicity, particularly from heavy metals. The Connection Between Toxicity and Sun Sensitivity Heavy metals such as lead, mercury, and cadmium  are known to accumulate in the body over time through food, water, air pollution, and everyday consum