Occurrence and dietary exposure to phthalates in the US population - a contextual review.

Esters of 1,2-benzene dicarboxylic acid (or phthalates) are general purpose plasticizers used in multiple polyvinyl chloride (PVC) consumer applications. Some of these plasticizers are permitted for safe use in a narrow subset of food packaging applications by global regulatory agencies, including the US FDA. Several US studies have reported the presence of trace concentrations of phthalates (parts per billion) in the diet.

Mechanisms of Impaired Lung Development and Ciliation in Mannosidase-1-Alpha-2 () Mutants.

Background: Ciliary defects cause heterogenous phenotypes related to mutation burden which lead to impaired development. A previously reported homozygous deletion in the gene causes lethal respiratory failure in newborn pups and decreased lung ciliation compared with wild type (WT) pups. The effects of heterozygous mutation, and the potential for rescue are not known.

Biliary-Atresia-Associated Mannosidase-1-Alpha-2 Gene Regulates Biliary and Ciliary Morphogenesis and Laterality.

Background/aims: Infectious and genetic factors are invoked, respectively in isolated biliary atresia (BA), or syndromic BA, with major extrahepatic anomalies. However, isolated BA is also associated with minor extrahepatic gut and cardiovascular anomalies and multiple susceptibility genes, suggesting common origins.

Methods: We investigated novel susceptibility genes with genome-wide association, targeted sequencing and tissue staining in BA requiring liver transplantation, independent of BA subtype.

The sub-chronic toxicity of a naphthenic hydrocarbon solvent in rats.

Cycloalkanes/naphthenes are constituents of complex hydrocarbon solvents, and hence an understanding of their toxicological profile is critical to establish safe limits for occupational exposures to these solvents. Although naphthenes are structurally related to and share a common metabolic fate with the straight and branched chain analogues, some toxicokinetic differences have been noted. The acute central nervous system response to volatile naphthenes in rodents has been shown to be slightly different compared to other alkane analogues.

Assessment of the potential human health risks from exposure to complex substances in accordance with REACH requirements. "White spirit" as a case study.

The European chemical control regulation (REACH) requires that data on physical/chemical, toxicological and environmental hazards be compiled. Additionally, REACH requires formal assessments to ensure that substances can be safely used for their intended purposes. For health hazard assessments, reference values (Derived No Effect levels, DNELs) are calculated from toxicology data and compared to estimated exposure levels.

The reciprocal calculation procedure for setting occupational exposure limits for hydrocarbon solvents: An update.

Hydrocarbon solvents are liquid hydrocarbon fractions, often with complex compositions. Due to the potential for human exposure, primarily to the more volatile solvents, substantial effort has been directed toward the development of occupational exposure recommendations. Because of the complex and variable nature of these substances, a proposed approach is to calculate occupational exposure levels (OELs) using an adaptation of the mixture formula developed by the ACGIH® in which "group guidance values" are assigned to similar constituents.

Characterization of the toxicological hazards of hydrocarbon solvents.

Hydrocarbon solvents are liquid hydrocarbon fractions derived from petroleum processing streams, containing only carbon and hydrogen atoms, with carbon numbers ranging from approximately C5-C20 and boiling between approximately 35-370°C. Many of the hydrocarbon solvents have complex and variable compositions with constituents of 4 types, alkanes (normal paraffins, isoparaffins, and cycloparaffins) and aromatics (primarily alkylated one- and two-ring species). Because of the compositional complexity, hydrocarbon solvents are now identified by a nomenclature ("the naming convention") that describes them in terms of physical/chemical properties and compositional elements.

The sub-chronic toxicity of regular White Spirit in rats.

Hydrocarbon solvents are mostly complex substances (UVCB) with carbon numbers in the range of approximately C5-C20. One of the most common types is a C9-C14 aliphatic solvent containing approximately 20% aromatics and commonly known as White Spirit in Europe and mineral spirits in the US. In previous repeated inhalation toxicity studies, White Spirit was reported to cause minimal systemic effects in most animal species with few effects other than male rat-specific kidney changes at levels up to approximately 2000mg/m(3).

The sub-chronic toxicity in rats of isoparaffinic solvents.

Results from a 13-week inhalation study in rats on a C10-C12 isoparaffinic solvent are compared to the results of repeated inhalation and oral toxicity studies of four other isoparaffinic hydrocarbon solvents. Statistically significant findings which were consistent across all studies included: nephropathy and small but significant changes in hematological parameters in male rats and liver enlargement in both male and female rats. The male rat kidney changes were due to an alpha 2u globulin process and not relevant for human health or risk assessment.