Q. I have been curious as to why Stanley Liggins wears dark glasses when he appears in court? I would presume it is due to a medical condition. — Susan, Davenport
A. Quad-City Times reporter Tara Becker has been covering the Stanley Liggins trial. She said, "Stanley (Liggins) had written to the judge earlier this year. He says in the letter that he wears the glasses because he has glaucoma, and he also had his left eye removed about 20 years ago."
To read the full letter, visit qctimes.com/askthetimes.
A reader from Muscatine questioned the accuracy of information provided by Stuart Schmitz, state toxicologist for the Iowa Department of Public Health, in Ask the Times on May 20.
"Please note the limestone dust is different than silica dust. You may google it.
"'Occupational exposures to respirable crystalline silica are associated with the development of silicosis, lung cancer, pulmonary tuberculosis, and airway diseases.'"
"National Institute for Occupational Safety & Health (NIOSH)
"'But I live on a farm, along a gravel road ... It's always dusty ...'
"'Respirable crystalline silica is a much more hazardous occupational exposure than limestone dust,' according to the Centers for Disease Control and Prevention (CDC). The current maximum recommended exposure limit for respirable limestone is 100 times higher than for respirable crystalline silica — and OSHA has proposed further cutting the silica limit by one-half.
"The information that you provided is inaccurate." — Dyrk, Muscatine, Iowa
A. We contacted Stuart Schmitz for a response. He said, "Yes, silica dust is much more hazardous than limestone dust. The current standards for respirable silica dust are 100 times more protective than for respirable limestone dust. Silica is a harder material than limestone with the potential for more jagged, cutting edges that would do greater damage to the interior of the lungs. Limestone has some solubility, while silica is insoluble in water. All this would contribute to the greater hazard potential of silica when compared to limestone when inhaled."
When asked about his statement in the May 20 Ask the Times column, Schmitz said, "My recommendation would essentially be the same for limestone. City and county officials should be aware of the OSHA and NIOSH standards for limestone dust of 5 mg/m3 for the respirable portion of the limestone dust and should require these standards to be enforced for the workers and require some type of controls to prevent excess exposure of limestone dust to the public. The health impacts from short-term exposure to limestone dust will not be long-term health impacts, but there will be short-term health impacts such as eye and lung irritation. People will underlying respiratory issues and the very young and very old will be impacted to a greater degree. These adverse impacts should lessen and individuals should recover after exposure to the dust stops."