A WATERSHED-LEVEL ECOLOGICAL RISK ASSESSMENT METHODOLOGY1

ABSTRACT: We present an ecological risk assessment methodology at the watershed level for freshwater ecosystems. The major component is a pollutant transport and fate model (a modified EUTROMOD) with an integrated uncertainty analysis utilizing a two-phase Monte Carlo procedure. The uncertainty analysis methodology distinguishes between knowledge uncertainty and stochastic variability. The model assesses the ecological risk of lentic (lake) ecosystems in response to the stress of excess phosphorus resulting in eutrophication. The methodology and model were tested on the Wister Lake watershed in Oklahoma with the lake and its trophic state as the endpoint for ecological risk assessment. A geographic information system was used to store, manage, and manipulate spatially referenced data for model input.     

Carbon Monoxide Levels in Kitchens and Homes with Gas Cookers

It always has been assumed that only a small amount of CO will be produced by a gas stove when mixture of air and gas are well adjusted and that that small amount will be dissipated by the home’s ventilation and by a combination of a fan and hood over the stove. However, preparation of meals may substantially increase CO. The immediate air supply may be progressively diminished when more than one burner is used and air supply may be partially cut off by vessels placed over the gas flame. The purpose of this investigation was to determine the amount of CO that may be expected to be produced during normal cooking. The experiment measured CO levels, using multiple burners with and without cooking vessels, and the rate of dissipation of the accumulated gas under various conditions of ventilation.     

Administration of Local Air Pollution Control Programs (Salaries and Qualifications of Personnel)

An attempt to develop medical air quality guides are recently made in Sweden. Even if air pollution is present in only fairly small amounts, problems frequently arise especially concerning nuisance reactions. Present regulations do not provide a basis for a standardized treatment of air pollution problems. The national air pollution situation was discussed and a survey of the literature was performed to collect data concerning current air pollutants. For sulfur dioxide a 30 day value of eight pphm and a two hour value of 25 pphm was recommended. It was further recommended to keep the carbon monoxide concentration as low as possible with an eight hour value of 30 ppm as an absolute maximum. For carcinogenic and mutagenic substances it was also recommended to keep the values as low as possible. Although available data did not support complete medical guides in all cases it was decided rather to have the above approximations than to leave the air pollution situation uncontrolled.     

The effect of navigational expertise on wayfinding in new environments

Becoming proficient at navigation in urban environments is something that we all aspire to. Here we asked whether being an expert at wayfinding in one environment has any effect on learning new spatial layouts. Licensed London taxi drivers are among the most proficient urban navigators, training for many years to find their way around a complex and irregularly-laid out city. We first tested how well they could learn the layout of an unfamiliar town compared with a group of non-taxi drivers. Second, we investigated how effectively taxi drivers could integrate a new district into their existing spatial representation of London. We found that taxi drivers were significantly better than control participants at executing routes through the new town, and representing it at a map-like survey level. However, the benefits of navigational expertise were not universal. Compared with their performance in the new town, taxi drivers were significantly poorer at learning the layout of a new area that had to be integrated with their existing knowledge of London. We consider reasons for this picture of facilitation and limitation, in particular drawing parallels with how knowledge acquisition occurs in the context of expertise in general.     

Some Applications of Microscopy to Air Pollution

The microscope as it has been and is now applied to air pollution work is discussed. A summary of the most common particulate sampling equipment is presented and distinctions as to the area of usage (suspended, or settled particulates) are made in each instance. Actual cases are discussed in which the polarizing microscope was used to determine identities and source of particulate pollutants. Particles from such sources as power plants, feed mills, and combustion sources are discussed and photomicrographs of known samples and unknown particles causing complaints are presented and compared as part of the discussion. References are given which deal with sampling equipment and microscopic analysis of various particulates.     

Brush and Trunk Burning Plant in the City of Detroit

For many years the City of Detroit was a flagrant violator of its own air pollution laws by the indiscriminate open burning of Dutch Elm diseased trees, brush and trunks. Cited for violation under the city’s air pollution control code as well as under threat of a private legal suit, the City administration approved a $250,000 expenditure for the design and installation of a unique six ton per hour brush and trunk burning incinerator plant. This plant was conceived by engineering personnel of the City Engineer’s office in consultation with engineering staff members of the Air Pollution Control Bureau. Information is provided on the basic plant layout and design, wet fly ash collector configuration, operating and maintenance experience, and recommended changes for any future similar installations. Stack emission test data are also reported. Due to the success of this plant, a similar plant is in the process of being constructed in another part of the city upon completion of which the City of Detroit will no longer be required to burn brush and trunk waste in open fires. The new plant has incorporated some design changes which should enable it to perform even more efficiently than the prototype unit and handle a wider variety of waste such as Christmas trees and wrecking waste. Because this plant is the first of its kind in the U. S. and the disposal of Dutch Elm diseased brush and trunks is a major problem in many urban areas, the experience of the City of Detroit should be of vital interest to many municipal officials.     

Seasonal variations in radionuclide transfer in a Mediterranean grazing-land ecosystem.

We made quarterly determinations of the transfer coefficients and effective transfer coefficients for the radionuclides 137Cs, 90Sr, 40K, 226Ra, 228Ra and 228Th over a full annual cycle, in a Mediterranean grazing-land ecosystem. The input and output fluxes of the radionuclides between the different compartments of this ecosystem were quantified for the following processes: root uptake; variation in root and aerial biomass; pasture production; translocation; leaf fall; efflux due to grazing action; resuspension and subsequent aerial deposition of radionuclides. We observed there to be a marked seasonal variation for this type of ecosystem in both the transfer coefficients and the radionuclide fluxes, which impedes the soil-plant transfer being characterized on the basis of values that are constant with time.     

The effects of ventilation on residential air pollution due to emissions from a gas-fired range

The use of indoor combustion appliances can cause an increase in the levels of many different pollutants. The work presented here shows the usefulness of a model for extrapolating environmental chamber results on pollutant emissions from combustion appliances to determine indoor pollutant concentrations in actual residences. In addition, the effects of infiltration, whole-house ventilation, and spot ventilation on pollutant levels are investigated. The results show that a range hood is the most effective means of removing pollutants emitted from a gas-fired range; removal rates varied from 60% to 87%.     

Culture,ethics, and the environment — Towards the New Synthesis

Summary This largely philosophical article argues that we need to examine the roots of our cultural worldview if we are to understand the causes of our global crises and current obstacles to desirable change. Calls for a new ethic are likely to be ineffectual in the absence of a challenge to the damaging dichotomy between fact and value that characterises our culture. However, the dominant worldview is under increasingly strong challege from organic systems thinking which has far-reaching implications, and which suggests that Western culture's dominant assumptions are not in accord with reality. If our culture, and individuals in it, are able to become more balanced, decisive desirable change could take place in society. This balance will involve the proper reintegration of ethical dimensions into thinking, based upon the recognition of the importance of the integrity of human communities and natural systems. This constitutes an emergent worldview and coherent philsophical framework to which many groups are already giving expression. It is imperative that this cultural change is understood and supported as it represents genuine hope for the future.After a teaching career in England and Canada, Stephen Sterling joined, as Assistant Director, the United Kingdom Council for Environmental Education (CEE). He was involved in writing the Education Report forThe Conservation and Development Programme for the UK, and has acted in an advisory capacity on a number of national and international documents on environmental education and environmental ethics. He has edited the CEE's journalReview of Environmental Education Developments for six years. The views expressed in this article are his own.     

过去10年来世界各地21世纪地方议程中的 住区经验：方法与汲取的教训

本文评述联合国人类住区中心推动 21世纪地方议程的经验 .它依据促进 21世纪地方议程举措的两个最主要的人类住区方案，即可持续城市方案 (SCP)和落实 21世纪地方议程方案过程中所取得的经验，对构成参与城市规划和管理的一个共同框架的几个不同阶段做了解释 .本文还提出了在全世界 40个城市所汲取的几点重要教训 .