A rationale for recycling

The decision as to whether to recycle discarded objects or not has traditionally been made on a simple financial basis. However, over the last few years a popular movement has sprung up which regards recycling as a good in itself, and this movement finds itself at odds with the present financial basis for recycling. In this paper a rationale for recycling is worked out in an attempt to resolve this conflict. It is concluded that the normal market signals do not provide a proper basis for recycling decisions and that this market failure must be corrected by government intervention. However, this intervention should not take the form of uncritical support for recycling. Rather the societal objectives of individual recycling proposals should be identified and the proposal should then be evaluated in terms of whether it would achieve these objectives more effectively than some alternative action.     

Are energy efficiency standards justified?

This paper develops an analytical framework for comparing the welfare effects of energy efficiency standards and pricing policies for reducing gasoline, electricity, and nationwide carbon emissions. The model is parameterized with US data and includes key externalities in the energy/transportation sectors and possible underinvestment in energy efficiency due to “misperceptions” over energy savings. Even with large misperceptions, the extra welfare gains from complementing efficient pricing policies with energy efficiency standards are zero for reducing gasoline and 5 percent for reducing electricity. And when viewed as substitutes, these standards forgo 60 percent or more of the potential welfare gains from corresponding pricing policies. A combination of energy efficiency and emissions standards is more than three times as costly as carbon pricing when there is no misperception over energy savings, and even with large misperceptions, combining carbon pricing with gasoline/electricity taxes is better than combining it with energy efficiency standards.     

A statistical approach to estimating driver responsibility in two-car crashes

A statistical model is developed relating driver age distributions in one-car and two-car crashes to the probability that both of the drivers in a two-car crash are similarly responsible for the crash as are drivers in a single-car crash. The model is applied to (a) passenger car crashes in the years 1975–1980 involving a driver fatality, compiled in the U.S. Fatal Accident Reporting System (FARS), and (b) all police-reported crashes occurring in North Carolina in 1979, supplied by the North Carolina Highway Safety Research Center. Appropriate national and North Carolina driver license data are used to estimate exposure to potential crashes as a function of driver age. The model is found to provide an adequate fit to observed driver age distribution in two-car crashes for both data sets. The results obtained from this fit to the model equations indicate that for two-car crashes involving a driver fatality, both drivers contribute to the responsibility for the crash in about 40% of cases, but for less severe two-car crashes, only one of the two involved drivers is generally responsible.     

Accumulation of bis(tributyltin) oxide by the mud crab, Rhithropanopeusharrisii

Accumulation of ¹⁴C labelled bis(tributyltin) oxide (TBTO) by the mud crab, $\text{Rhithropanopeus}$$\text{harrisii}$, was determined through short-term exposure to labelled water and food. The potential for trophic accumulation during chronic low level exposure is emphasized.     

Evaluating threats to an endangered species by proxy: air pollution as threat to the blue swallow (<Emphasis Type="Italic">Hirundo atrocaerulea</Emphasis>) in South Africa

Background, aim, and scope  

The blue swallow (Hirundo atrocaerulea) is one of the most threatened bird species in southern Africa. Among terrestrial birds, its plumage is known to be the most water repellent, an adaptation to foraging on the wing in dense fog. Despite this unique adaptation, the nesting success of the blue swallow at the Blue Swallow Natural Heritage Site (BSNHS) is lower during years with high incidence of fog. As the phenomenon is not observed at other nesting sites, we hypothesized that this is due to changes in the air chemistry at the BSNHS. In the immediate proximity of the BSNHS, plantations of exotic trees (e.g., pines and eucalypts), rich in volatile organic compounds (VOCs), are dominant features. In addition, air pollution from the Johannesburg area is transported with the surface winds and mix with VOCs released from exotic trees. Together with the high humidity and high elevation, these conditions may result in the formation of sulphonates. Sulphonates are strong detergents, and the presence of these in the fog could lead to decreased water repellence of the plumage. This study was performed in order to determine the occurrence and distribution of sulphonates in the BSNHS and to compare these with sulphonates formed in other locations in South Africa. Because the blue swallow is endangered, pine needles were used as proxy to detect formation of sulphonates.     

ESTIMATING REFERENCE EVAPORATION IN THE CENTRAL VALLEY OF CALIFORNIA USING THE LINACRE MODEL1

ABSTRACT: The Linacre (1988) model for calculating evaporation from open water or well-watered surfaces only requires inputs of air temperature, latitude and elevation, and windspeed if it is available. The model was developed using data collected at a large number of sites in different climatic regions of the world, while independent tests of the model have shown it to be suitable for estimating evaporation in a variety of locations. This study was intended to contribute to the broad goal of evaluating temperature-based evaporation models for use in California by testing the Linacre model in the agriculturally intensive Central Valley. Observed monthly mean reference evaporation (E_o) and meteorological data for periods ranging up to 72 months were obtained from 25 California Irrigation and Management Information System (CIMIS) stations distributed throughout the Central Valley. Uncalibrated and calibrated Linacre models were used to estimate monthly mean reference evaporation, and the performance of each model was evaluated using indices that quantified the random and systematic errors and overall model performance. The accuracy of the radiation and ventilation components of the model were evaluated separately. The uncalibrated model was found to systematically overestimate E_o with most of the model error being attributed to the ventilation component. Calibration of the radiation and ventilation components removed most of the systematic model errors, and the root mean square error for monthly mean E_o was 0.676 mm day^?1 (16.8 percent of the mean observed value). (KEY TERMS: reference evaporation; Linacre model; irrigation scheduling.)     

PHYTOPLANKTON IN THE FOX CHAIN OF LAKES1

ABSTRACT: As part of a comprehensive water quality investigation on the Fox Chain of Lakes during May to October 1975, water samples from the Chain and Cedar Lake (reference) at 25 locations were collected weekly or bi-weekly to determine the species and densities of algae. The results have been evaluated for algal composition, density, and succession for each location. Sixty-four algal species were recovered from 414 samples. The number of species per sampling location varied from 10 at Channel Lake and Lake Marie to 26 on Fox Lake (main) and Grass Lake. Blue green algae were predominant and occurred at 25 of the 25 sampling stations. They consisted mainly of Aphanizomenon flos-aquae. The only flagellate of importance was Ceratium hirundinella, and significant concentrations of this organism were limited to Channel Lake and Lake Catherine. The only green alga bloom was created by Ulothrix variabilis on the waters of Pistakee Lake. Diatoms were quite significant on the shallower water bodies. Algal densities ranged from about 25 to 14,000 cts/ml. The highest count occurred on Mineola Bay. Other high counts (>10,000 cts/ml) observed were waters taken from Channel Lake, Grass Lake, and Fox Lake (main). In Grass Lake, 60 percent of the collections had algal densities in excess of 2,000 cts/ml. Most of these were the diatom Cyclotella meneghiniana.     

ASSESSMENT USING GIS AND SEDIMENT ROUTING OF THE PROPOSED REMOVAL OF BALLVILLE DAM,SANDUSKY RIVER,OHIO1

ABSTRACT: The proposed removal of Ballville Dam was assessed by (1) using a new Geographic Information Systems (GIS) based method for calculating reservoir sediment storage, (2) evaluating sediment properties and contamination from core data, and (3) assessing downstream impacts from sediment routing calculations. A 1903 (pre‐dam) map was manipulated using GIS to recreate the reservoir bathymetry at time of dam construction and used in combination with a detailed 1993 bathymetric survey to calculate sediment volumes and thickness. Reservoir sediment properties and geochemistry were determined from 14 sediment vibracores. Annual sedimentation rates varied from 1.7 to 4.3 g/cm²/yr based on Cesium‐137 (¹³⁷Cs) and Lead‐210 (²¹⁰Pb) geochronology and dated flood layers. The pore fluid geochemistry (Ba, Co, Cu, Mn) of four cores showed surficial enrichments in Cu, while Co and Mn show secondary peaks within the sediments. GIS calculations showed that a designed channel through the former reservoir able to accommodate the 10 percent Probable Maximum Flood (PMF) would require removing approximately 0.35 million m³ of sediment (27 percent of the reservoir fill), either by dredging at a cost of up to $6.3 million or by releasing fine grained sediment downstream. A sediment routing model was applied for the critical 6 km downstream using four cross sections. The sediment routing model predicts that, for flows exceeding minimum Mean Daily Flow (1924 to 1998 data), greater than 90 percent of this sediment would be transported through downstream reaches into Lake Erie (Sandusky Bay).