Human exposure to pollutants in Poland.

Serious environmental problems caused by decades of mismanagement of Poland's natural resources have been brought to light in recent years. All environmental media--air, water, food, and soil--have been burdened with toxic chemicals. Some environmental problems are so severe that the sources of pollution and the mitigation techniques needed are obvious, requiring no further research, but rather common sense, monies, and determination to implement the necessary controls and mitigation procedures. This paper will not address these obvious cases. Rather it will address that spectrum of environmental problems which requires a better understanding of public health risk in order to develop effective risk management strategies. Because these problems are numerous and monies limited, policy makers will need to set priorities both for research projects and control options. Using environmental concentration data presently available from Poland (especially for air), the paper will estimate human exposures, will point out research and monitoring needs, and hopefully, will lend credence to the concept that environmental policies and risk reduction strategies will be most effective if the Total Human Exposure Concept is used as the guiding scientific principle in risk assessment and management programs.

Seasonal variations and trends in concentrations of filter-collected polycyclic aromatic hydrocarbons (PAH) and mutagenic activity in the San Francisco Bay area.

Air monitoring in the San Francisco Bay Area was carried out to measure outdoor community air concentrations of polycyclic aromatic hydrocarbons (PAH) and mutagenic activity (mutagenicity) in particulate organic matter (POM). Monitoring began in 1979 and is currently conducted at six stations. PAH and mutagenicity tests were performed on organic extracts prepared from high volume (hi-vol) filters composited every four months, by meterological season. PAH were determined by high pressure liquid chromatography (HPLC) with fluorescence and ultraviolet detection. Mutagenicity was measured in the Ames Salmonella bioassay using strain TA98 with and without metabolic activation. The nine-year mean concentration of benzo(a)pyrene (BaP) was 0.4 ng/m3. The mutagenicity of this amount of BaP accounted for only about 0.2% of the observed mutagenicity in POM and other measured PAH accounted for even less. Concentrations of PAH and mutagenicity were three to nine times higher during the winter than during other seasons. Year-to-year wintertime trends in several PAH were also seen. Early in the 1980s, winter concentrations of BaP and benzo (g,h,i)perylene increased. However since the mid-1980's, their concentrations have fallen. The decrease in PAH concentrations may be the result of an increasing proportion of vehicles with relatively low organic emissions. In contrast to PAH, mutagenicity did not show significantly year-to-year time trends.

The relation between policy and research planning.

The crucial role of total exposure assessment (TEA) in environmental epidemiology, risk assessment, risk management, and disease diagnosis and treatment has been appreciated only in recent years, and then by a relatively small number of policy makers and scientists. Thus TEA is a relatively new research field with a limited data base. As a result, research needs cover a broad range. However, setting research priorities with limited resources is a problem. Agencies usually develop criteria to set priorities. The criteria often have at least one element in common, namely, that the research be compatible with policy goals. However, policies are developed, at least in part, using research data, thus making policy and research planning an iterative process. TEA, by definition, is related to multi-media and multiple routes of exposure. Because of this, research planning can be hampered by differences in policies of programs dealing with different media and routes of exposure. Thus it is important to develop better ways to facilitate communication among policy makers, research planners, and researchers. This paper will argue that one such way is the proper use of the basic scientific tenet of hypothesis testing in planning, executing, and evaluating research. The paper will discuss this tenet, and recommend that exposure researchers use it, not only to improve the quality of their individual research but also to provide a better mechanism for setting priorities for research projects.

Mutagenicity of fine (less than 2.5 microns) airborne particles: diurnal variation in community air determined by a Salmonella micro preincubation (microsuspension) procedure.

A simple modification of the Salmonella liquid incubation assay previously developed for detecting mutagens in urine was used to determine mutagenic activity of airborne particulate matter. The modification consists of adding ten times more bacteria (approximately 10(9) per incubation tube) and five to ten times less metabolic enzymes compared to the plate incorporation method. The mixture volume is approximately 0.2 ml, and the mixture is incubated for 90 min before pouring it according to the standard protocol. The modified procedure (micro preincubation or microsuspension) was approximately ten times more sensitive than the standard plate incorporation test for detecting mutagens in air particulate extracts and approximately ten to 31 times more sensitive for the chemical mutagens 2-nitrofluorene, 4-nitroquinoline-N-oxide, 2-aminofluorene, and benzo(a)pyrene in bacterial strain TA98. Mutagenic activity was detected in particle extracts obtained from 1 m3 of air (17 micrograms of extract) or less. This microsuspension procedure was applied to air particulate samples collected with low-volume (15-50 liters per min) virtual-dichotomous air samplers. Mutagenic activity was associated exclusively with fine particles (aerodynamic diameters of less than 2.5 microns). Diurnal patterns of mutagenic activity (TA98 revertants per cubic meter air) were investigated by measuring filter extracts from 2-hr samples collected in three San Francisco Bay Area cities during the summer or fall of 1982. Four criteria pollutants--lead, nitrogen dioxide, ozone, and sulfur dioxide--were simultaneously sampled at one location. Mutagenicity from fine particles sampled at this location was highly correlated with lead and much less correlated with nitrogen dioxide, ozone, and sulfur dioxide. The microsuspension procedure is applicable in testing samples of limited mass.

Epidemiological monitoring of environmental lead exposures in California State Hospitals.

Blood lead screening of 8062 state hospital residents in California revealed 143 residents with excessive lead levels (greater than or equal to 30 micrograms/dL). This screening was part of the Childhood Lead Project and was performed in 1978. The purpose of this study was to identify "critical" lead sources in California State Hospitals. Accurate identification is crucial if subsequent abatement programs are to be effective. The strategy involved the following sequence of steps: 1) Selection of cases based on blood lead and erythrocyte protoporphyrin screening. 2) Determination of pica habits and environmental exposures through interviews with ward's staff and/or parents. 3) Measurement of lead levels in environmental samples reflecting exposures. 4) Interpreting these data in order to identify critical lead sources. 5) Reducing exposure to critical lead sources. 6) Following up of cases and controls to validate the effects of this strategy. A group of 36 lead-burdened cases with pica (30-60 micrograms Pb/dL blood) and 36 matched controls (PbB less than 20 micrograms/dL) were selected from among the developmentally disabled residents of two California State Hospitals. These subjects were studied in order to identify the lead sources to which they were exposed and to abate the major ones. Three major lead sources were found in the state hospitals: wall and furniture paints (100-45,400 micrograms Pb/g paint); surface soil (33-570 micrograms Pb/g soil); educational format was presented to all involved staff. The results have indicated a trend towards lower lead intake by the lead-burdened cases. In one of the two hospitals a "lead-free unit" had been established. All the lead-burdened cases were transferred to this unit in August 1981. A few months later the blood lead levels of all the cases dropped below 30 micrograms/dL. Initial epidemiological monitoring indicated where there were preventable hazards, which abatement efforts succeeded in reducing. Further monitoring of such problems is indicated in this and other developmentally-disabled populations.

Identification of lead sources in California children using the stable isotope ratio technique.

Two case studies are presented which apply the lead isotope ratio method to the identification of lead sources in 12 Oakland, California children. One study examined lead sources in 10 children, ages 3 to 15 yr, living together as an extended family in dilapidated housing close to a busy freeway. Eight children had elevated blood lead levels (greater than or equal to 30 micrograms/dl) and 6 children also had elevated erythrocyte protoporphyrin levels (greater than or equal to 50 micrograms/dl). A second case study examined 2-yr-old male twins, both with elevated blood lead and erythrocyte protoporphyrin levels, living in a modest, but well maintained inner city duplex apartment. Paint and surface soil samples collected in and around both households had high lead concentrations. Paint concentrations ranged from 2.9 to 273 mg/g and surface soil concentrations from 0.48 to 7.1 mg/g. The isotopic ratios of lead in the blood of these children were close to the average lead ratios of paints from exterior walls and to the lead ratios of surface soils in adjacent areas where the children played. In both case studies, the data suggest that the lead in the soil was derived mainly from weathering of lead-based exterior paints and that the lead-contaminated soil was a proximate source of lead in the blood of the children.

The identification and elimination of a potential lead hazard in an urban park.

During development of a park in Oakland, California, a potential public helath hazard due to lead in the soil (approximately 1,000 to 100,000 ppm) was identified through cooperative sampling and analysis efforts of the staffs at the county and state health departments. Analysis of samples collected at various locations and depths in the park, coupled with a three-dimensional model of the lead values obtained, indicated steps necessary to eliminate the hazard. The county undertook the abatement program, and with the elimination of the health hazard, the park development has been completed. Concomitant blood lead screening of neighborhood children failed to establish the park as a source of elevated lead in any of the children tested.