The Use of Herr Four-and-a-Half Clearing Fluid for the Rapid Microscopic Examination of Thick Sections of Normal and Neoplastic Tissues

We have demonstrated that Herr's 4¹/₂ clearing fluid, developed for use with plant tissues, can be successfully used for the microscopic examination of thick sections of normal and neoplastic mammalian tissues. Rat Novikoff hepatoma, rat liver, and human colon and skin samples were fixed in Bouin's, stained with iron hematoxylm, treated with Herr's 4¹/₂ clearing fluid and examined by phase contrast miaoscopy. Tissue architecture and cytological detail were easily observed by focusing through tissue Sections as thick as 70μ. The method permits rapid microscopic examination of mammalian tissues and enables the investigator to detect readily morphological abnormalities within a tissue.     

Public health risk analysis for ambient polycyclic aromatic hydrocarbon exposure surrounding a petrochemical complex in Curaçao

Abstract

Antiquated petroleum refining methods may exacerbate polycyclic aromatic hydrocarbons (PAHs) in ambient air. There is currently an aging, yet active refinery on the island of Curaçao that has been the subject of public health concern. The objective of this study was to determine if ambient PAHs surrounding this refinery exceeded public health guidelines and investigate potential public health risks by calculating risk probability estimates. A number of recommended guidelines for the protection of public health from ambient PAHs were exceeded in Curaçao. Cumulative lifetime risk estimates for carcinogenic effects exceeded the upper bound level of acceptable risk at sites located both upwind and downwind of the petrochemical complex in 2011 and decreased to within the range considered acceptable in 2014. Risk probability estimates were highest for children and either exceeded or were approaching the upper bound advisory levels in 2011. Results indicate inhalation risks are higher at sites located downwind from the petrochemical complex compared to those upwind. This emphasizes the potential for higher risk probability estimates for residents that may have higher susceptibility, warranting the need for further health assessments in these populations and underscores the importance for continued monitoring of PAH sources and levels in Curaçao.