
Dioxin Emission Factors for the Incineration of Different Medical Waste Types
Previous research works showed that to protect public health, hospital incinerators should be provided with equipment to reduce atmospheric emissions. Most hospital incinerators do not possess such equipment, so efficient methodologies should be developed to evaluate the safety of incineration procedures. Emission factors can be used for an easy estimation of the parameters defined in legislation. Nevertheless, the actual knowledge is very scarce, mainly because previously published emission factors do not include enough information about the incinerated waste types and the respective proportion in incinerated mixture. The existence of different waste classifications also reduces the usefulness of previously published results. This study reports the first dioxin emission factors estimated for the incineration of medical waste, segregated in different types according to the classification of the Portuguese legislation. The main purpose was to evaluate the influence of waste type on emission factors, assessing how useful they are if not associated to the composition of the incinerated mixture. The study also allowed analyzing the correspondence between different waste classifications that are being used, comparing the estimated emission factors with the sole results previously published for specific waste types but segregated according to a different classification. The influence of the incinerated waste type and segregation practices on the concentration and amount of emitted dioxin was assessed, as well as the influence of segregation practices on the amount of wastes that must be incinerated. To estimate eventual hazards for human health, dioxin concentrations in combustion gas flow were compared with the respective legal limits.
Concentration of Atmospheric Pollutants in the Gaseous Emissions of Medical Waste Incinerators
ABSTRACT The purpose of this paper is to quantify the production of medical waste from a general hospital and to evaluate the atmospheric pollutant concentrations in gaseous emissions associated with its incineration. A 3.8 kg (bed.day)-1 production of medical waste was estimated for 1998; its incineration is related with an ash production of 0.3-0.4 kg (bed.day)-1. The concentrations of atmospheric pollutants were estimated using emission factors, comparing the effluents with and without control of atmospheric pollutants. The calculated concentrations were compared with the emission limits established by Portuguese legislation. The results indicate that, if there is no control of atmospheric pollutants, their concentrations exceed the established limits. This is observed even if correct operation and maintenance procedures are used. The emission concentrations of dioxins are higher than the Portuguese emission limit, which is particularly worrying due to the high toxicity of some of these compounds. Generally, it is possible to reduce pollutant concentrations if appropriate control equipment is used. The conclusions obtained clearly justify the great concern regarding air pollution associated with medical waste incinerators currently operating in Portugal.
An Internet-based Real-time Heavy Rainfall Display System
A new storm warning system, which can be accessed through the Internet and by cellular phones is described. At the time of a heavy rainfall for disaster prevention, it is important that every resident understand how heavy is that rainfall. A real-time heavy rainfall display system designed for all of Japan provides such information (http://www.disaster-i.net/rain/). In that system values for 1-hour precipitation, 24-hour accumulated precipitation, etc. are displayed at every observatory. Advantages are that not only the latest observations but differences from the historical highest records can be seen. Almost all information is displayed by characters so that users have easy access to the system even when the communication network is crowded. Access date for the six months after the system opened shows that the average daily number of accesses of the top page was 306, and the largest number 3078. The maximum number for daily access to all the pages was about 21,500. This is about 2% of the number obtained on the same day for a similar system operated by the Ministry of Land, Infrastructure and Transport (http://www.river.go.jp/).