Spatial and temporal trend evaluation of ambient concentrations of 1,3-butadiene and chloroprene in Texas.

This paper provides information on 1,3-butadiene (BD) and chloroprene as atmospheric pollutants in Texas and reviews available emission estimates and monitoring data. Ambient BD concentrations in most areas of Texas are predominantly influenced by on-road and off-road vehicular emissions or biomass burning, since BD is a product of combustion. However, large industrial point sources of BD emissions in Texas locally influence ambient concentrations. Total industrial BD emissions to the atmosphere in Texas for 2003 were estimated at 695 tonnes per year (TPY), approximately 70% of the total reported national industrial BD air emissions. Since 1998, there have not been any large industrial sources of chloroprene emissions in Texas, and total industrial chloroprene emissions for 2003 was estimated at only 0.09 TPY. Chloroprene was never detected at air monitoring sites. In 2003, the Texas Commission on Environmental Quality (TCEQ) monitored BD ambient air concentrations at 57 sites, some of which have been operational since 1992. These air monitors provide information on ambient BD concentrations in Texas and allow spatial and temporal trend evaluation. In 2003, annual average concentrations at monitoring sites in Texas ranged from less than the reporting limit of 0.01 to 3.2 parts per billion by volume (ppbv) with an overall average of 0.2 ppbv. This overall average is reduced to 0.1 ppbv if BD data from monitoring sites in Port Neches and Milby Park in Houston, which are located downwind of significant point sources of BD, are excluded. Ambient air monitoring has been conducted in Port Neches and in Milby Park in Houston since 1996 and 1999, respectively. At the Port Neches monitor, trend evaluation indicates that ambient concentrations of BD have declined since 1996 due to cooperative agreements with industries emitting BD. Annual average BD concentrations at the Port Neches monitor decreased from 8.3ppbv in 1996 to 1.3 ppbv in 2003, giving an 8-year average of 3.8 ppbv. Annual average BD concentrations at the Milby Park monitor varied between 2.1 and 4.4 ppbv from 1999 through 2003, giving a 5-year average of 3.1 ppbv. The results of cancer cluster studies based on Cancer Registry 1995-2001 incidence data and 1993-2002 mortality data conducted by the Texas Department of State Health Services for zip codes 77017/77012 (Houston) and 77651 (Port Neches) will be presented.

Occupational exposure to butadiene, isoprene and chloroprene.

Workers are exposed to butadiene, isoprene and chloroprene in the manufacture of these monomers and in their use in the production of various elastomers. These include styrene butadiene rubber, polybutadiene, polyisoprene, butyl rubber and neoprene. Monomer production and extraction are done in typical closed chemical process units where low background levels of the monomers are the result of minor leaks in valves and pumps. Occasionally, higher levels occur as a result of planned or unplanned events that cause releases. Polymer production is also a closed process, but the occasional clogging of pipes and equipment with polymer requiring maintenance operations where some release is likely occurs much more often than for monomer production. For this reason, exposure levels are generally higher on polymer production units. Polymer finishing is essentially an open process, but almost all monomer should have been stripped from the polymer before finishing. Where small amounts of solvents or monomers remain in the polymer and are volatilized in finishing, they are captured by vapor control systems. As a result, exposures in finishing are typically low. Measured levels of exposure in recent years are presented. In general, modern levels of exposure are well below OSHA, ACGIH and other applicable limits. Few measurements were made prior to the 1970s, but epidemiological estimates made by modeling suggest that levels could have been quite high in the 1940s and 1950s. In these years, manual reactor cleaning was common, and pumps often leaked.

A fatal intoxication by chloroprene.

UNLABELLED: Objective Chloroprene, 2-chloro-1,3 butadiene, is a volatile synthetic liquid. The chloroprene monomer is extremely reactive and is used for the production of latexes and synthetic rubber such as Neoprene. Up to now an acute lethal human exposure has been described only once in the literature [19]. The intoxication is associated with nervous system depression, pulmonary edema, narcosis, and respiratory arrest. Case report A 29-year-old chemistry company worker was found unconscious in an empty vessel (depth: 3m) used for chloroprene. The man was dressed in shoes, trousers, a helmet and a respiratory mask. The upper part of the body was unclothed. In spite of reanimation, the man died three hours later in a hospital. MATERIAL AND METHODS: All analyses were performed by headspace gas chromatography (HS/GC/FID). In addition, brain, muscle and myocardial muscle were analysed by headspace GC-MS. Results and discussion Autopsy findings: The cause of death could not be determined as the macromorphological findings were unspecific. Toxicology findings The calibration curve of chloroprene in serum shows linearity from 1.0 to 200 µg/ml (r(2)=0.9999) using benzene as internal standard. The LOD is 0.28 µg/ml, the LLOQ is 0.99 µg/ml. Tissues and body fluids were stored at -20 °C till the analysis. Chloroprene was quantified after addition of benzene as the internal standard. It was found in nearly all tissues and body fluids except in the urine and lung. The highest concentrations were detected in the kidney, liver, myocardial muscle and especially in the brain. Furthermore, hexanal was found in all samples except in the urine. The amount of hexanal in some specimens is high, especially in the lung, bile, gastric content and myocardial muscle. Conclusion We assume that a significant amount of chloroprene was not only inhaled but also absorbed through the skin because the man wore a respiratory mask. Presumably the accident would not have happened if the works safety protocols had been followed. The reason why high concentrations of hexanal were found in the tissues could not be clarified.

[Gas chromatographic detection of 2- chlorbutadiene- 1,3 and 2,3-dichlorbutadiene- 1,3 in skin wash-off]. / Gazochromatograficheskoe opredelenie 2-khlorbutadiena-1,3 i 2,3- dikhlorbutadiena- 1,3 v smyvakh s kozhnykh pokrovov.

Highly sensitive, selective method of 2-chlorobutadiene-1,3 and 2,3-dichlorobutadiene-1,3 detection by means of gas chromatography in the skin wash-off is worked out. The sensitivity is 0.2 microgram for 2-chlorobutadiene-1,3 and 1 microgram for the 2,3-dichlorobutadiene-1,3.