We prove global existence and uniqueness of smooth solutions to a nonlinear system of parabolic equations, which arises to describe the evolution of the chemical aggression due to the action of sulphur dioxide on calcium carbonate stones. This system is not uniformly parabolic and only some energy estimates are available. Nevertheless, global (in time) results are proven using a weak continuati...

Septic tanks [1] are enclosed areas made for accumulation of decomposed domestic wastes, sewerage and its resultant gases. Sewer gases can be both toxic and non-toxic. Its major component is Methane [2], which can be extremely toxic in high concentrations. Sewer gas is a mixture of Hydrogen Sulphide, Ammonia, Carbon-dioxide, Nitrogen dioxide, Sulphur dioxide and sometimes, even carbon monoxide....

1. The products of the lactoperoxidase-catalysed oxidation of thiocyanate by hydrogen peroxide were sulphate, carbon dioxide and ammonia. Cyanate, sulphite and a compound showing increased extinction at 235mmu (the ;235 compound') were intermediate oxidation products. 2. Two of the intermediates acted as electron acceptors in the oxidation of NADH(2). Thus NADH(2) was oxidized by sulphite in th...

BACKGROUND Acute exposure to air pollution has been linked to myocardial infarction, but its effect on heart failure is uncertain. We did a systematic review and meta-analysis to assess the association between air pollution and acute decompensated heart failure including hospitalisation and heart failure mortality. METHODS Five databases were searched for studies investigating the association...

Industrial exposure to gases and fumes may produce a wide variety of respiratory damage including tracheobronchial inflammation and parenchymal damage.' Tracheobronchial inflammation is reported, particularly after exposure to chlorine, ammonia, and sulphur dioxide. Interstitial pneumonitis has been associated with the inhalation of oxides of nitrogen,2 cadmium,3 manganese,4 mercury,5 and resin...

Plants assimilate inorganic sulphate for the bio­ synthesis of sulphur containing compounds. The enzymes required for reduction are found pre­ dominantly in the plastids which provide the necessary energy and the reductants. Sulphate re­ duction like nitrate or carbon dioxide assimilation is endergonic; for comparison, N 0 3 reduction to ammonia requires +347 kJ mol1 and C 0 2 re­ duction +478 ...

Communication of the complex relationship between air pollutant exposure and ill health is essential to an air pollution information system. We propose a novel air pollution index (API) system based on the relative risk of the well-established increased daily mortality associated with short-term exposure to common air pollutants: particulate matter (PM10, PM2.5), sulphur dioxide, ozone, nitroge...

The Pollution Effects on Asthmatic Children in Europe (PEACE) study is a multicentre study of the acute effects of particles with a 50% cut-off aerodynamic diameter of 10 microm (PM10), black smoke (BS), sulphur dioxide (SO2) and nitrogen dioxide (NO2) on the respiratory health of children with chronic respiratory symptoms. The study was conducted in the winter of 1993/1994 by 14 research centr...

BACKGROUND Health impacts of poor environmental quality have been identified in studies around the world and in Canada. While many of the studies have identified associations between air pollution and mortality or morbidity, few have focused on the role of health care as a potential moderator of impacts. This study assessed the determinants of health care access and utilization in the context o...