Introduction

The following papers were presented at a technical session held during the 76th APCA Annual Meeting and Exhibition in Atlanta, Georgia in June 1983. The session, which focussed on the relationship between atmospheric deposition and forest activity, was organized by J. S. Jacobson and S. B. McLaughlin, Jr., and sponsored Jby APCA's TT-8 Acid Deposition Committee.     

Honorary Memberships

Honorary Memberships are conferred by the Air Pollution Control Association on persons of widely recognized eminence in some part of the field of air pollution control or who have rendered especially meritorious service to the Association. Honorary Memberships were awarded this year to Dr. Leonard Greenburg and Mr. Milton Reizenstein, both past presidents of APCA.     

Prevention Of Significant Deterioration A Critical Review

Prevention of significant deterioration has been a subject of study and discussion for about ten years. An extensive survey of the legislative and legal aspects of this concept is presented in this review. The growth of the concept and its implementation are subjected to critical scrutiny.     

Acid Particles and the Tracheobronchial Region of the Respiratory System—An “Irritation-Signaling” Model for Possible Health Effects

This paper explores some detailed mechanistic hypotheses for the possible action of acid particles on the tracheobronchial region of the human respiratory system. Because of the buffering capacity and volume of mucus produced per day it appears doubtful that ordinary ambient exposures to acid particles could markedly change the overall pH of tracheobronchial mucus considered as a whole. However it is possible that individual acidic particles could contain enough acid to deliver localized “irritant signals” that could be the triggers for enhanced mucus secretion and cell division in sensitive portions of the bronchial tree, and thereby contribute to the processes involved in chronic bronchitis.

Depending on the exact pH depression required for a “signal” to be perceived by the tracheobronchial epithelium, the acid content of the incoming particles per unit weight, and the effect of neutralization by ammonia in the upper respiratory tract, the minimum size of an acidic particle required to deliver a perceptible signal might range from about 0.4 to 0.7 microns for portions of the epithelium that are frequently swept by 4-micron mucus droplets. (For unprotected epithelium, however, it is conceivable that the minimum effective size for acid particles could be less.) Since particle number per unit weight declines dramatically with increasing particle size, the most potent fraction of particles in terms of signals delivered per μg/m³is likely to be just above the minimum size that is needed to produce an effective signal. The model developed here makes predictions of the relative potency of particles of different size and acid delivery capacity that could be tested in both experimental animal systems and human epidemiological studies.     

Comparison of micrometeorological and two-film estimates of air–water gas exchange for alpha-hexachlorocyclohexane in the Canadian archipelago

The air-sea gas exchange of alpha-hexachlorocyclohexane (α-HCH) in the Canadian Arctic was estimated using a micrometeorological approach and the commonly used Whitman two-film model. Concurrent shipboard measurements of α-HCH in air at two heights (1 and 15 m) and in surface seawater were conducted during the Circumpolar Flaw Lead study in 2008. Sampling was carried out during eight events in the early summer time when open water was encountered. The micrometeorological technique employed the vertical gradient in air concentration and the wind speed to estimate the flux; results were corrected for atmospheric stability using the Monin-Obukhov stability parameter. The Whitman two-film model used the concentrations of α-HCH in surface seawater, in bulk air at 1 and 15 m above the surface, and the Henry's law constant adjusted for temperature and salinity to derive the flux. Both approaches showed that the overall net flux of α-HCH was from water to air. Mean fluxes calculated using the micrometeorological technique ranged from -3.5 to 18 ng m(-2) day(-1) (mean 7.4), compared to 3.5 to 14 ng m(-2) day(-1) (mean 7.5) using the Whitman two-film model. Flux estimates for individual events agreed in direction and within a factor of two in magnitude for six of eight events. For two events, fluxes estimated by micrometeorology were zero or negative, while fluxes estimated with the two-film model were positive, and the reasons for these discrepancies are unclear. Improvements are needed to shorten air sampling times to ensure that stationarity of meteorological conditions is not compromised over the measurement periods. The micrometeorological technique could be particularly useful to estimate fluxes of organic chemicals over water in situations where no water samples are available.     

PET bottle use patterns and antimony migration into bottled water and soft drinks: the case of British and Nigerian bottles

While antimony has been reported to migrate from PET bottles into contents, reports on bottled water and soft drinks usage and PET bottle reuse patterns are currently unavailable in the literature. Bottle use conditions and patterns are important determinants of antimony migration. In this work a survey assessing the pattern of bottle use and reuse in Britain and Nigeria was undertaken. The survey findings influenced the design of laboratory experiments that assessed the migration of antimony from PET bottles into water and soft drinks. Typical storage durations for bottled contents between purchase and opening for use were 7 days or less. However storage of up to one year was reported. Bottle reuse was high and similar for the two countries with reuse durations being higher in Nigeria. The antimony concentration in 32 PET bottle materials from Britain and Nigeria were similar and ranged between 177 and 310 mg kg(-1). For 47 freshly purchased British bottled contents antimony concentration ranged between 0.03 and 6.61 μg L(-1) with only one sample exceeding the EU acceptable limit. Concentrations of Cd, Ge, Zn, Al, Be, Ti, Co and Pb were also measured. At realistic temperatures of 40 and 60 °C antimony concentration in deionised water in bottles remained below the EU acceptable limit even after 48 h exposure. The limit was exceeded for most exposures at 80 °C. Concentration of antimony in some bottled contents exceeded the EU limit after 11 months of storage at room temperature. Bottle aging and increase in bottle volume were associated with decreased migration of antimony from bottles.     

Occupational exposures,delivered doses and exposure limits for chromium and nickel†

The interaction of HCH (50 mg/kg) and dietary protein levels on microsomal drug metabolizing enzymes system and liver lipids were studied in the rats for 90 days. The results indicated that rats fed a lower protein diet and HCH has a higher rate of mortality, lower rate of growth and an increased liver weight. A significant induction in the hepatic microsomal aminopyrine‐N‐demethylase, p‐nitroanisole‐O‐dealkylase, benzo(a)pyrene hydroxylase and glutathione‐S‐transferase activity was observed in pesticide treated animals as compared to control animals. The pathological changes observed in liver of HCH treated animals consisted mainly of necrosis and fatty degeneration of hepatocytes. HCH also induced the significant accumulation of cholesterol, triglycerides, phospholipid and total lipid in liver in low protein diet animals. Protein accelerates the metabolism of HCH, resulting in a decrease of HCH concentration with the increase of dietary protein level. A close correlation existed between lipid accumulation, induction of drug metabolizing enzyme system and deposition of HCH in liver.