Air pollution can damage grapevines in many parts of the world. Air pollutants arise from industrial gases and particles, exhaust gases including lead, agrochemicals, and fires. Principal pollutants are hydrogen fluoride, sulfur dioxide, ozone, and smoke, and in restricted areas phenoxy herbicides such as 2,4-D (see auxins) applied to nearby crops. Hydrogen fluoride has reduced vineyard yields in many countries. While the leaves can accumulate high levels of fluoride, it is not translocated to the fruit. Mourvèdre is particularly sensitive to this type of pollution, while Carignan is tolerant. A reported eucalyptus character of wine is sometimes blamed on such trees near the vineyard.