Unexpected toxic interactions in the freshwater amphipod Gammarus pulex (L.) exposed to binary copper and nickel mixtures

To document the toxicity of copper and nickel in binary mixtures, freshwater amphipods Gammarus pulex were exposed to the metals given independently or as mixtures. Toxicity to Cu alone was relatively high: 96-h LC₁₀ and LC₅₀ were found at 91 and 196 μg L^?1, respectively. Toxicity to Ni alone was very low, with 96-h LC₁₀ and LC₅₀ of 44,900 and 79,200 μg L^?1, respectively. Mixture toxicities were calculated from single toxicity data using conventional models. Modeled toxicity was then compared with the measured toxicity of the binary mixture. Two kinds of mixtures were tested. Type I mixtures were designed as combinations of Cu and Ni given at the same effect concentrations, when taken independently, to identify possible interactions between copper and nickel. In type II mixtures, Cu concentrations varied from 0 to 600 μg L^?1 while the nickel concentration was kept constant at 500 μg L^?1 to mimic conditions of industrial wastewater discharges. Ni and Cu showed synergic effects in type I mixtures while type II mixtures revealed antagonistic effects. Low doses of Ni reduced Cu toxicity towards G. pulex. These results show that even for simple binary mixtures of contaminants with known chemistry and toxicity, unexpected interactions between the contaminants may occur. This reduces the reliability of conventional additivity models.     

Furazolidone residues in chicken and swine tissues after feeding trials

Abstract

Broiler chickens and swine fed furazolidone in their diet were sacrificed, and samples of liver, kidney, skin/fat and muscle were harvested and analyzed for furazolidone residue. Chickens fed 200 g of furazolidone/ton of feed were withdrawn from treatment 21, 14, 7, 5, 3, or 0 days before slaughter. Birds withdrawn from medication more than 5 days prior to slaughter had no residues in any of the tissues sampled. One of the 12 birds in each of the 5 day and 3 day withdrawal groups had detectable residues in the skin/fat. Seven of the 12 birds in the 0 day withdrawal group had residues of <2 ppb in skin/fat samples. Chickens fed 400 g furazolidone/ton of feed were withdrawn from treatment 0 days before slaughter. Residues of 0.7 to 3.5 ppb were found in the skin of these birds; residues were not found in other tissues. Swine were fed 300 g furazolidone/ton of feed for 2 weeks or 150 g/ton for 5 weeks. They were withdrawn from treatment 10, 7, 5, 3, or 0 days before slaughter. Tissue samples taken from these swine did not contain detectable furazolidone residues.     

A Method for Using Air Pollution Measurements and Public Opinion to Establish Ambient Air Quality Standards

Air quality was comprehensively evaluated by means of sampling at 21 locations over metropolitan Birmingham during a period of one year. Thousands of integrated samples of three common atmospheric gaseous pollutants and two common particulate pollutants were collected and analyzed. Following the year of sampling in 1964, a random household survey was completed by conducting personal interviews at more than 7200 households over metropolitan Birmingham. Statistical reduction of household survey results by census tract and by neighborhood area provided domestic fuel and waste burning emission data as well as public (resident) opinion on specific air pollution effects. The relationship between ambient air quality and neighborhood opinion of air pollution effects on health and property are evaluated statistically. Ambient standards are suggested which are based upon those air pollution levels shown to have adverse effects on approximately one-third of the people.     

Soiling Potential—A New Method for Measuring Smoke Emission

There is a growing interest in effects of sub-micron, nonsettling particles in the atmosphere among air pollution control agencies throughout the country. This type of pollution, generally referred to as the “soiling index” of the atmosphere, is produced primarily by the incomplete combustion of fuels. The measurement procedure has been fairly well standardized, the values being reported as Cohs or Ruds per 1000 linear feet of air. Using a similar technique, a method of quantitating smoke emission in objective terms first demonstrated by W. C. L. Hemeon in 1953, has been applied to source testing at several operating plants by the Cincinnati Division of Air Pollution Control. The source strength will be called “soiling potential” while the effect in the general atmosphere is termed “soiling index.” The soiling potential unit is Rud-ft² per cubic foot exhaust gases or Rud-ft² per unit of fuel input. The “Soiling Potential” sampler is described and results of tests are given. Included is the use of soiling potential in quantitating smoke emission from single sources and for constructing area wide inventory of smoke emission. The use of an area wide smoke emission inventory in Rudft2 in a simple diffusion model for calculating the soiling index (Rud-ft²/1000 cu ft) in the general atmosphere at a given point is explored.     

Measuring the Improvements in the Control Aspects of Programs Aided by Federal Grants

Ambient air standards, emission standards, and program activities are considered in a search for appropriate indices for measuring program progress and effectiveness. The authors suggest that such indices can best be based on data related to weight of emissions. Several methods for expression accomplishment are presented for consideration.     

Reducing Emissions from Refuse Disposal

Estimates indicate that approximately 2.6% of the total atmospheric pollution in this country may originate as a result of refuse disposal. Although this may appear to be a comparatively low figure, it is important to note that refuse disposal is a universal problem: wherever we go, be the area urban, or rural, waste must be disposed of and in most cases the methods of disposal produce air pollution. Tabulated data indicates that the per capita rate of production has been increasing annually. In the city of Hartford, the quantity of refuse that is being burned in the municipal incinerator has been increasing at a rate of 5%/year. A comparison of the air pollutants emitted from open burning at a refuse disposal area, backyard burning and incineration of refuse in a municipal multiple chamber incinerator indicates that the quantity of pollutants emitted from the latter source is much less than those emitted from the other sources. The effect of having legislation with, enforcement authority and a program for regular inspections, has resulted in marked improvements of refuse disposal operations in Connecticut since June, 1966. Most of the burning still being done at refuse disposal areas is limited to only brush and demolition material. A multi-purpose incinerator is presently under construction in the city of Stamford, Conn. It is planned to demonstrate that not only bulky wastes and auto bodies, but also liquid wastes can be burned in the same unit without creating any adverse effect on the environment. This incinerator will be provided with an electrostatic precipitator for removing particulate emissions.

New methods of refuse disposal which are being tried are briefly described in this paper. All these methods tend to reduce or eliminate air pollution along with eliminating the health hazards normally related with open face dump type of operations.

The continual technological progress and improvements in methods of manufacture, packaging, and marketing of consumer products along with the economic, population, and industrial growth of the nation has resulted in an ever-mounting increase and change in the characteristics of the mass of material being discarded by the purchaser. In May 1967, a Three-State Conference on Air Resource Management was held at the City College of the City University of New York. This conference consisted of a number of panels or committees which discussed specialized areas of the problem of air pollution and its control. A portion of the introductory remarks from the panel report of the Solid Waste Committee1 is as follows:     

Frank A. Chambers

Abstract

This work assessed the usefulness of a current air quality model (American Meteorological Society/Environmental Protection Agency Regulatory Model [AERMOD]) for predicting air concentrations and deposition of perfluorooctanoate (PFO) near a manufacturing facility. Air quality models play an important role in providing information for verifying permitting conditions and for exposure assessment purposes. It is important to ensure traditional modeling approaches are applicable to perfluorinated compounds, which are known to have unusual properties. Measured field data were compared with modeling predictions to show that AERMOD adequately located the maximum air concentration in the study area, provided representative or conservative air concentration estimates, and demonstrated bias and scatter not significantly different than that reported for other compounds. Surface soil/grass concentrations resulting from modeled deposition flux also showed acceptable bias and scatter compared with measured concentrations of PFO in soil/grass samples. Errors in predictions of air concentrations or deposition may be best explained by meteorological input uncertainty and conservatism in the PRIME algorithm used to account for building downwash. In general, AERMOD was found to be a useful screening tool for modeling the dispersion and deposition of PFO in air near a manufacturing facility.     

The Estimation of Personal Exposures to Air Pollutants for a Community-Based Study of Health Effects in Asthmatics—Design and Results of Air Monitoring

In order to provide reliable pollutant and meteorological exposure estimates for an epidemiological study of asthmatics residing in two Houston neighborhoods, a dedicated three-tier air monitoring system was established. This consisted of fixed site ambient air monitoring at the center of each study area, a mobile van performing simultaneous indoor and outdoor measurements at selected residences of study participants, and a limited amount of direct personal monitoring for half of the participants. Monitored pollutants Included all criteria pollutant gases, as well as aeroallergens, aldehydes, TSP, and IP. Laboratory analyses provided concentrations of sulfate, nitrate, and trace elements. Continuous measurements of several meteorological parameters also were obtained. Intensive quality assurance and data validation efforts resulted in a high percentage of valid data for most pollutants. Ozone was the only measured pollutant that exceeded the NAAQS during the six-month (May to October) study period. The monitoring scheme allowed important pollutant concentration differences to be detected between day and night, between Indoors and outdoors, and among various indoor environments. The use of these monitoring data in combination with personal activity and household characteristics data to generate estimates of personal exposures for the epidemiological analysis will be described in a subsequent paper.     

Analysis of Ambient Concentrations of Organic Vapors with a Passive Sampler

Volatile organic compounds can contribute to the failure of electronic equipment in both switching offices and data centers. They can also be useful indicators of ventilation needs. Only within the past decade have ambient concentrations of volatile organics been measured routinely. In standard sampling approach, a pump is used to pull a known volume of air through an adsorbent. This study examines a sampling procedure that does not use a pump, but instead depends on molecular diffusion for eventual contact between the vapor phase compounds and the charcoal sorbent (passive sampling). The technique is both simpler and less expensive than active sampling with a pump. This method has been validated for low-level sampling over extended time intervals. This study demonstrates that collected amounts vary linearly with airborne concentrations for sampling intervals in excess of four weeks: even after eight weeks of sampling at typical ambient concentrations, the amount of material collected does not approach the capacity of the sorbent. The method is applicable for concentrations spanning six orders of magnitude; reproducibility averages 13 percent of the mean value; and the sensitivity is excellent (0.06 μg/m³ or roughly 0.015 ppbv for a compound with a molecular weight of 100). The procedure has already been used successfully to monitor indoor air quality at almost a dozen telephone office and data center sites.