Greater than how many ppm fluoride in water has a 60% chance of causing fluorosis?

The correct answer indicates that water containing greater than 6 ppm of fluoride carries a significant risk, specifically a 60% chance, of leading to dental fluorosis, especially in children whose teeth are still developing. Fluorosis is a condition that results from excessive fluoride consumption during the enamel formation stage, leading to changes in the appearance of the teeth.

Research has indicated that fluoride levels above certain thresholds significantly increase the likelihood of fluorosis. While levels of 0.7 ppm to 1.2 ppm are typically recommended for optimal dental health, exceeding approximately 6 ppm can pose serious risks. The context here is crucial; as fluoride levels rise, so does the risk for developmental effects on dental enamel.

Thus, if water has fluoride levels surpassing 6 ppm, the probability of developing fluorosis reaches this notable threshold. This emphasizes the importance of monitoring fluoride levels in community water supplies to prevent dental issues associated with excessive exposure.