Environmental impact of hydraulic fracturing in the United States tuberculosis, kidney disease, autoimmune disorders and airway disease such as asthma and bronchitis. Most of these debilitating and potentially fatal diseases are preventable with occupational control measures regarding respirable crystalline exposure. Hydraulic fracturing uses abundant amounts of sand in the process of fracturing as part of the hydraulic fluid. The fracturing fluid consists of a base fluid, proppant and chemical additives. The majority of proppant used in fracturing are made of silica (sand). Truck loads of sand are delivered to the sites, then loaded to sand movers that are then transferred to a blender that mixes the hydraulic fluid. The
Gel pen some have finger grips of rubber or plastic. The size of the nib or pen tip ranges from to . Compared to other inks, gel ink has higher viscosity, which supports a higher proportion of pigments in the medium. The pigments are typically copper phthalocyanine and iron oxides, and the gel is made up of water and biopolymers, such as xanthan gum and tragacanth gum, as well as some types of polyacrylate thickeners. The pigments are opaque, and gel pens are available in several bright and pastel colours, as well as opalescent, metallic, and glittery colours which show up clearly