Howard A. Bridgman

Evaluating rainwater contamination and sources in southeast Australia using factor analysis

Abstract Factor analysis is used to evaluate inorganic ion relationships to provide a qualitative determination of continental sources of rainwater contamination in the Hunter Region, New South Wales, Australia. The rain water was collected between October 1984 and March 1986 at 32 sites and forms the database for the Hunter Region Acid Rain Project. The results show that soil and animal/fertilizer sources determine rainwater quality over most of the Hunter Region, and dominate as the major sources when the entire data set is analysed as a whole. When individual sites are analysed, the industrial emissions factor is important at six adjacent locations in the Middle Hunter, suggesting some transport of sulphate and nitrate from industrial sources 50 to 80 km to the east and southeast may be occurring. Factor analysis by rainfall event provides similar results to site analysis, with only 4 events out of 34 dominated by the industrial emissions factor. The results indicate that rainwater quality is influenced by local and regional sources, and not by long-range transport from Sydney, 175 km to the south. Comparison of the Hunter Region ion relationships to those from a more heavily acidic area, the northeast U.S.A. (MAP3S/RAINE Network), demonstrate some similarities in associations but the correlations associated with the hydrogen ion are better defined in the U.S. data set.

Could climatic change have had an influence on the Polynesian migrations

Abstract A hypothesis is presented that a change in climate after 1250 AD from a period of optimal climate for long-distance voyaging (the Little Climatic Optimum, 750–1250 AD) to a period of less favourable and finally inhospitable climate for long-distance voyaging (the Little Ice Age, 1400–1850 AD) influenced the Polynesian migrations (300–1400 AD). The Little Climatic Optimum, with its persistent trade winds, clear skies, limited storminess, and consistent Walker Circulation may have been an ideal setting for migration. The Little Ice Age with its increased variability in trade winds, erratic Walker Circulation, increased storminess, and increased dust from volcanism may have helped [prevent migration. Such changes in climate would influence the migration pattern through physical perception and decision making by the Polynesians, rather than having a direct impact.

Fog and rainwater composition in rural SE Australia

In order to determine if pollutants from the Wollongong-Sydney-Newcastle industrial area in southeastern Australia can be transported northwards, affecting precipitation quality to the north, a preliminary study of fog and rainwater quality was carried out from January to April 1989. Samples were collected from two sites in the state of New South Wales, one in the Barrington Tops and the other near Dorrigo. These samples were analyzed for the cations sodium, calcium, magnesium, potassium, and ammonium, and the anions chloride, nitrate, sulfate, methanesulfonate, formate and acetate, as well as pH and conductivity.The mean pH of fogwater from the two sites was 5.48, compared to 5.62 for rainwater. Fogwater also had concentrations of ions 2–6 times those in rainwater. For both fog and rain the ions sodium, chloride, magnesium, and methanesulfonate at both sites were essentially entirely sea-salt derived, while only 5–50% of potassium, calcium, and sulfate were derived from sea-salt. The acid-base balance was adequately described (r=0.76) by a balance between the acidity contributed by sulfuric and nitric acids, neutralized by the alkalinity of ammonia and (soil dust-derived) calcium carbonate. Comparing this study with others, both within Australia and overseas, fog and rainwater at both sites are not polluted, with acidity only slightly greater than background and concentrations of anthropogenic pollutants very low, and with sea-salt influences accounting for the majority of ionic loading.

Acid rain studies in Australia and New Zealand

This paper reviews the results of the few scattered acid rain studies in Australia and New Zealand. Large scale spatial discussions are not possible, so discussion, focussing on wet deposition, is limited to rainwater acidity and chemistry on a regional and local basis. Rainwater samples were mainly collected on a daily or event basis, and some attempt was made to ensure contamination from dry fallout in all cases. Rainwater acidity can be divided into three regimes: non-tropical urban, non-tropical rural and tropical rural areas with the Tropic of Capricorn the dividing line between tropical and non-tropical. In Sydney, representative of non-tropical urban, local emissions of acid gases, particularly sulphate and nitrate, resulted in an average pH of 4.4. At several non-tropical rural locations, pHs average between 5.0 and 5.7, indicative of global background levels. Tropical rural pHs average about 4.5, due mainly to natural acidity caused by vegetation release of volatile organic acids. These values indicate that rainwater in this region contains from 2 to 12 times less acidity than in the northern hemisphere where acid rain is a problem. Rainwater chemistry is dominated by ocean influences along the coast and soil and vegetation influences inland. Elevated levels of sulphate and nitrate in rainfall of the Latrobe Valley and the Hunter Valley may be due to power station and industrial sources located there, but do not prove to be a problem.

Exploring lifetime occupational exposure and SLE flare: a patient-focussed pilot study.

Introduction Environmental effectors, such as ultraviolet radiation exposure, infection and stress, have been established as having a role in exacerbating lupus symptoms. However, unpredictable patterns of flare events still remain a mystery. Occupational effectors have also been suggested as having a contributing role; however, they are not widely researched. In this paper we report a pilot study designed to generate focus areas for future research regarding occupational exposures and systemic lupus erythematosus (SLE). Methods The study explored potential links between exposures and the occurrence of patient-reported flare events in 80 Australian women with SLE (American College of Rheumatology (ACR) criteria classified). Specifically, the study assessed the hypothesis that occupational exposure is associated with significant changes in the likelihood of lupus flares. Lifetime employment history was analysed with the Finnish Job Exposure Matrix (FINJEM), 40 different semiquantified exposure class estimates for a wide number of occupations based on probability of exposure (p≥5%=exposed) were analysed with the construction of negative binomial regression models to test relationships between occupational agents and flare days. A backward stepwise elimination was used to generate a parsimonious model. Results Significant associations were noted for exposure classes of manual handling burden, (p=0.02, incidence rate ratio (IRR) 1.01), Iron (p=0.00, IRR 1.37), wood dust (p=0.00, IRR 3.34) and asbestos (p=0.03, IRR 2.48). Conclusion Exposure assessment results indicated that occupations, such as nursing, with a high manual handling burden, posed increased risk to patients with SLE, however, the greatest risk was associated with wood dust and iron exposure with teachers and specialist labourers.

Seasonal differences in the shortwave radiation budget at Newcastle, N.S.W.

Summary Comparisons of shortwave radiation budget parameters between summer and winter, 1978, at Newcastle indicate some important differences. Total radiation depletion under industrial emissions in the city compared to a rural site in summer, 8.3 per cent, is more than double that of winter, 3.5 per cent. Reductions of direct beam radiation in the city in summer were 18.6 per cent, double that of winter, 9.0 per cent. The diurnal pattern of higher direct and total radiation depletion with high solar zenith angles in summer is not repeated in winter. Diffuse radiation estimates were 28.3 per cent higher in the city compared to the country in summer, and 19.3 per cent higher in winter. Reflected radiation was a function of surface cover with no pollution influences discernable. Except where urban total radiation reductions in the city were greater than 10 per cent, net shortwave radiation in the city was higher because of lower urban surface reflection. It is suggested that differences in the meteorologic...

A simple wet-only rainfall collector

Details of an inexpensive event-actuated sampler used in the Hunter Region (Australia) Acid Precipitation Project are described. The sampler is designed for non-freezing conditions and is labor rather than material intensive. Cost of parts is approximately

Mesoscale spatial variability of sulfate in air and rainwater at St. Louis

120 (Australian).

Rainwater acidity and ion concentration correlations in a midwest storm system

Sulfate concentrations in rainwater and in air measured on four summer days at St. Louis were highly variable, both spatially or temporally. Maximum/minimum ratios of aerosol SOinf4sup−varied by up to a factor of 9, and those in rainwater by a factor of 3 on the average. Generally, SOinf4sup−concentration patterns in air and rainwater were similar, and consistent with wind direction and the location of sources. Direct relationships between SOinf4sup−in air and in water were evident on two of the individual days, but not for all days together. The non-uniformity of the SOinf4sup−pattern plus consideration of possible sources of SOinf4sup−suggests that nucleation of SOinf4sup−particles must be a major cause of S scavenging, with some possible influence from sub-cloud impaction.

Turbidity at Newcastle, NSW, 1978

The pH and the concentrations of sulfate, nitrate, ammonia, and calcium in rainwater were measured for two periods of a single midwest rainstorm which occurred over a mesometeorological network in central Illinois on 24–25 July 1979. Regression analysis was used to compare ion concentrations with rainfall amount, and ion balance was used to compare cation and anion concentrations at individual sites. Only the ions SO42- and NO3- show any significant relationship to rainfall amount, decreasing as rainwater amounts increase (r=−0.57 and −0.60, respectively). During the first period of the rainstorm, a sequential sampler measurements allowed the calculation of detailed temporal variations in SO42-, pH, and rain rate. SO42- decreased, and pH increased as the rate increased and the opposite temporal pattern occurred as the rain decreased at the end of the period. Reasons for these variations are discussed.