Airborne Particulate Lead Research Articles

Airborne particulate lead and children's mental functioning

Lead is a highly toxic metal that is pervasive in the environment in industrialised countries. There is universal agreement that at some level of exposure, lead damages the haematopoietic, renal, and neurological systems. However there is less agreement about how much lead can be tolerated without harm. The use of leaded petrol was phased out between 1976 and 1996 in the United States, and was eliminated in the European Union by 2000, but concern is growing that petrol remains an important source of exposure in many countries, especially in Africa and Asia. Motivated by this concern, the Seychelles Bureau of Standards implemented an air quality monitoring project to measure airborne lead in Victoria, the capital, beginning in January 1998. In this paper, we describe the potential dangers of human exposure to lead, focusing on the neurobehavioural effects in children. We describe some of the common and not so common sources of lead in the environment, emphasizing exposure from inhalation of airborne lead particles from automobile exhaust. The Seychelles Ambient Air Quality Monitoring Programme is described, including the collection and analytical methods used to measure the lead concentrations in these samples. We present the findings from this investigation and discuss their public health implications.

Bioaccessibility of lead in airborne particulates from car battery repair work.

The bioaccessibility of Pb in air particulate matter from two car battery repair workshops in Kumasi (Ghana) was measured (64 full shift personal aerosol samples). An artificial lung lining fluid simulant (Hatch solution) was applied for leaching the bioaccessible fraction in half of the samples, the other half was leached with synthetic gastric juice. At both locations, the Pb solubility (median) in gastric juice (89% and 92%) is substantially higher than in Hatch solution (4.9% and 5.6%). The high solubility of Pb in gastric juice may be related to the presence of Pb oxides. The low bioaccessibility of Pb in Hatch solution is in good agreement with previous work on mine tailings, urban aerosol, car exhaust, welding fumes and indoor dust. The high bioaccessibility of Pb in the gastrointestinal tract underpins the importance of improving the personal hygienic behavior at the workplace. It is recommended that air monitoring of Pb should include the extrathoracic aerosol fraction using inhalable aerosol samplers, as particles of this size fraction are most likely transferred to the gastrointestinal tract in addition to the non-lung-soluble particles transported from the lung by mucociliary and phagocytosis clearance.

Environmental health risk assessment of ambient lead levels in Lisbon, Portugal: A full chain study approach

The multi-causality interactions between environment and health are complex and call for an integrated multidisciplinary study approach. Emerging computational toxicology tools that link toxicology, chemistry, environmental sciences, biostatistics, and computer sciences are proving to be very useful for integrated full-chain human health risk assessments. In this study we use a newly developed computational tool - the 2FUN player to conduct a full-chain assessment combining measured ambient air lead concentrations with multi-media modelling and PBPK simulations to estimate the health risks from ambient air levels of lead in air-borne particulates (PM10) in Lisbon, Portugal. Ambient air Pb concentrations were used together with local climate variables in the 2FUN atmospheric model to calculate the amount of Pb deposited (wet and dry) onto soil. The 2FUN environmental and PBPK models were then used to calculate the Pb concentration in various biota (leafy vegetables, root vegetables, grain, potatoes, and fruits) produced in the area as well as the amount of Pb a typical adult would inhale and ingest during this ten-year assessment period. The PBPK model of the 2FUN player was used to calculate the Pb levels in the various body systems. Our results showed a low health risk from Pb exposures. It also identified that ingestion of leafy vegetables (i.e. lettuce, cabbage, and spinach) and fruits contribute the most to total Pb blood levels. This full chain assessment approach of the 2FUN player is likely to be very useful for local health risk assessment studies (i.e. EIA and SEA studies).

Lead Exposures from Car Batteries—A Global Problem

In “Mass Lead Intoxication from Informal Used Lead Acid Battery Recycling in Dakar, Senegal,” Haefliger et al. (2009) described a problem throughout the developing world that is both tragic and only now beginning to be understood with respect to its extent and effect. Eighteen children (and more since) died from acute lead poisoning in late 2008 in Dakar. These poisonings occurred because the individuals recycling car batteries melted slag without appropriate controls and without having any understanding of the toxicity of lead. Most of these recyclers were women who brought their children to their work sites without knowing the risks. These problems are not restricted to Senegal. Without much effort, investigators from Blacksmith Institute have identified another 22 sites worldwide that are similar to this one. The identified sites are in cities in poor countries, especially in the tropics (e.g., the Dominican Republic, Philippines, Panama, El Salvador, Guatemala, India, Ghana, Jamaica) (Blacksmith Institute 2009). Epidemiologic studies of exposed populations, such as the one in Senegal reported by Haefliger et al. (2009), are urgently needed to characterize exposures and identify related health effects. An earlier example of such a study was conducted in the Dominican Republic at Haina (also known as Bajos de Haina), which has been called the “Dominican Chernobyl.” This community is near an abandoned lead-acid battery recycling smelter, and most of the residents showed signs of lead poisoning. The Haina site, as well as the surrounding area, was the scene of severe lead poisoning in the 1990s. In March 1997, 116 children were surveyed, and 146 children were surveyed in August 1997. Mean blood lead concentrations were 71 μg/dL (range, 9–234 μg/dL) in March and 32 μg/dL (range, 6–130 μg/dL) in August (Kaul et al. 1999). The study revealed that at least 28% of the children required immediate treatment and 5% had lead levels > 79 μg/dL, putting them at risk for severe neurologic sequelae at the time of the study. In the United States, the action level for blood lead concentration is 10 μg/dL (Centers for Disease Control and Prevention 2007; U.S. Environmental Protection Agency 2000). The scientific findings from Haina (Kaul et al. 1999) drove a collaborative cleanup of this site, which has recently been completed. The Blacksmith Institute helped locate funding, worked closely with local authorities, and provided technical assistance to assure the cleanup was adequate. We are currently beginning a similar cleanup project in Dakar, at the site studied by Haefliger et al. (2009). Almost all large urban centers in the developing world have a problem with recycling used lead acid batteries, and hundreds of thousands, if not millions, of children are exposed to lead from battery recycling. In humid conditions, car batteries need to be replaced every 2 or 3 years, and car use is increasing throughout the world, which will result in even more used batteries. Thus, this problem deserves our immediate and serious attention.

Spark-Induced Breakdown Spectroscopy: A New Technique for Monitoring Heavy Metals

This paper presents the development and testing of a new real-time monitoring technique for heavy metal aerosols and particulates in air based on spark-induced breakdown spectroscopy (SIBS). The technique is based on temporally resolved atomic emission resulting from excitation of the aerosol-laden air sample in a high-energy electrically generated spark. A complete prototype monitor comprised of spark power supply, sample chamber, bandpass-filtered radiometric detector, and computer for real-time data acquisition and display has been assembled, calibrated, and tested. The lower limits of detection for lead and chromium are 10 μg/m3. The monitor has been successfully applied as a continuous emissions monitor for lead and chromium in a simulated combustion flue gas at a joint EPA/DOE test, for fugitive chromium emissions above a hard chrome plating tank, and for airborne particulate lead at an indoor firing range. The monitor has also demonstrated the capability to detect cadmium, mercury, selenium, antimony, arsenic, uranium, and thorium.

Determination of Lead Associated with Airborne Particulate Matter by Flame Atomic Absorption and Wave-Length Dispersive X-Ray Fluorescence Spectrometry

The lead content of airborne particulate matter was determined by flame atomic absorption spectrometry (FAAS) following digestion with a mixture of nitric acid and hydrogen peroxide and also by wave-length dispersive x-ray fluorescence (WDXRF). The extraction procedure was checked by analyzing a standard reference material of airborne particulate matter (NIST, SRM — 1648). It was concluded that lead can quantitatively (98%) be extracted from airborne particulate matter by the leaching process. A five-stage sequential extraction was performed to assess the potential mobility of lead associated with airborne particulate matter. Comparison of the airborne particulate lead measured by WDXRF to that measured by FAAS showed a good agreement. The WDXRF method requires no time-consuming sample preparation or use of environmentally unfriendly solvents. The technique is suggested for direct determination of lead in airborne particulate matter in air pollution studies.

Evaluation of a Chemical Spot-Test Kit for the Detection of Airborne Particulate Lead in the Workplace

A commercial rhodizonate-based test kit was evaluated for its potential use in the detection of lead in airborne particulate samples at work sites. Over 350 air samples were collected at abrasive blasting lead paint abatement sites using cellulose ester membrane filters and personal sampling pumps. The filter samples were tested with the chemical spot test and then analyzed by graphite furnace atomic absorption spectrophotometry. No positive readings were recorded for lead masses below 1.3 µg Pb/filter, and no negative readings were observed for lead amounts above 8.1 µg Pb/filter. Experimental data were statistically modeled in an effort to estimate the performance parameters of the spot test kit. The identification limit of the kit was found to be approximately 3.6 µg/filter sample. For lead mass values above approximately 10 µg Pb/filter, 95% confidence of a positive reading was found; while 95% confidence of a negative reading was found for lead masses below approximately 0.6 µg Pb/filter. Based on the results of this study the rhodizonate-based test kit for lead demonstrates potential for use in field screening for lead in personal breathing zone and area air samples.

Evaluation of a chemical spot-test kit for the detection of airborne particulate lead in the workplace.

A commercial rhodizonate-based test kit was evaluated for its potential use in the detection of lead in airborne particulate samples at work sites. Over 350 air samples were collected at abrasive blasting lead paint abatement sites using cellulose ester membrane filters and personal sampling pumps. The filter samples were tested with the chemical spot test and then analyzed by graphite furnace atomic absorption spectrophotometry. No positive readings were recorded for lead masses below 1.3 micrograms Pb/filter, and no negative readings were observed for lead amounts above 8.1 micrograms Pb/filter. Experimental data were statistically molded in an effort to estimate the performance parameters of the spot test kit. The identification limit of the kit was found to be approximately 3.6 microgram/filter sample. For lead mass values above approximately 10 micrograms Pb/filter, 95% confidence of a positive reading was found, while 95% confidence of a negative reading was found for lead masses below approximately 0.6 micrograms Pb/filter. Based on the results of this study the rhodizonate-based test kit for lead demonstrates potential for use in field screening for lead in personal breathing zone and area air samples.

Determination of lead on the airborne particulates of urban Valencia city

A method for the determination of lead in airborne particulates by graphite furnace atomic absorption spectrometry after extraction with HCl-HNO3 (120–150°C) is described. Particulate lead levels in the atmosphere have been measured in samples collected throughout a year, sampling has been made at eleven sites within the city of Valencia. The results obtained in this study show that annual means of lead levels are within the range of 0.526 to 7.033 μg/m3 depending upon the sampling site. Lead levels are higher in winter and autumn. Lead and nitrogen oxide levels are well correlated.

Lead concentrations in airborne particulates and blood in the area of Thessaloniki, Greece

The concentration of lead in airborne particulates and blood, has been measured in the area of Thessaloniki, during a period of one year. The air pollution caused by lead is still comparatively low. Concerning the lead concentration in blood from different groups of individuals, the levels don't exceed the safe limits.

Airborne lead and trace elements in an indoor shooting range: A study of the DC national guard armory pistol range

AbstractConcentrations of airborne particulate lead in an indoor pistol range far exceeded the recently revised Occupational Safety and Health Administration target standard of 50 μg/m3, often by two or three orders of magnitude. A substantial fraction (40 to 50%) of the lead occurred on respirable‐size particles (diameter ≤ 2 μm). Significantly elevated levels of Sb, Cu, As and Ba also resulted from the firing of .38 and .45 caliber pistols. The high levels of respirable, toxic elements observed indicate a potentially serious exposure for users and, in particular, the operators of such facilities.

AIRBORNE LEAD AND TRACE ELEMENTS IN AN INDOOR SHOOTING RANGE: A STUDY OF THE DC NATIONAL GUARD ARMORY PISTOL RANGE

Concentrations of airborne particulate lead in an indoor pistol range far exceeded the recently revised Occupational Safety and Health Administration target standard of 50 μg/m3, often by two or three orders of magnitude. A substantial fraction (40 to 50%) of the lead occurred on respirable-size particles (diameter ≤ 2 μm). Significantly elevated levels of Sb, Cu, As and Ba also resulted from the firing of .38 and .45 caliber pistols. The high levels of respirable, toxic elements observed indicate a potentially serious exposure for users and, in particular, the operators of such facilities.

Air pollution associated with airports

Air quality in the vicinity of airports is examined with particular reference to a detailed study of Gatwick Airport (UK). Ambient air concentrations of carbon monoxide, hydrocarbons (total and non-methane), oxides of nitrogen, smoke and airborne particulate lead have been measured at seven locations around the airport. The results obtained have been compared with ambient air quality guidelines, where available, and with results from other monitoring sites in the UK. It is concluded that the airport cannot be considered to be a significantly more important contributor to average pollutant ground-level concentrations than other sources in the area.

Determination of lead in airborne particulates using direct introduction of filter paper by graphite furnace atomic absorption spectrometry

Determination of lead in airborne particulates using direct introduction of filter paper by graphite furnace atomic absorption spectrometry

Trends of Airborne Particulate Lead in Ontario: 1971–1979

Trends of Airborne Particulate Lead in Ontario: 1971–1979

The determination of organic and inorganic lead compounds in urban air by atomic-absorption spectrometry with electrothermal atomization

A method for the simultaneous determination of inorganic and organic lead compounds in air is described, together with some results from its application at different sampling sites. Air-borne particulate lead is collected on a cellulose filter. Organic lead vapours are trapped in an iodine monochloride solution, placed behind the filter. A fraction of the cellulose filter is subjected to low-temperature ashing, after which the lead content in the residue is measured by electrothermal atomic-absorption spectrometry. The organolead material absorbed in the iodine monochloride solution, is determined by solvent extraction and electrothermal atomic-absorption spectrometry. For a 6-h sampling period, detection limits of the order of 10 ng m -3 for inorganic and 8 ng m -3 for organic lead materials may be obtained.

Household surface lead dust: its accumulation in vacant homes.

House dust has been suspected as a source of lead in the exposure of children, particularly those whose blood lead levels are in the moderately elevated range. The means by which household surface lead accumulates is at present not clear. By towel wipe sampling, 24 vacant houses in urban Rochester and Buffalo, New York, were examined for lead content on windowsills, floors, and other surfaces. High yields of lead were obtained from windowsills and floor areas adjacent windows. When washed and resampled, these areas yielded greatly reduced lead values. It is suggested that surface lead may represent a deposit phenomenon. The entry of exterior airborne particulate lead around the loose-fitting windows of older homes appears possible.

Household Surface Lead Dust: Its Accumulation in Vacant Homes

House dust has been suspected as a source of lead in the exposure of children, particularly those whose blood lead levels are in the moderately elevated range. The means by which household surface lead accumulates is at present not clear. By towel wipe sampling, 24 vacant houses in urban Rochester and Buffalo, New York, were examined for lead content on windowsills, floors, and other surfaces. High yields of lead were obtained from windowsills and floor areas adjacent windows. When washed and resampled, these areas yielded greatly reduced lead values. It is suggested that surface lead may represent a deposit phenomenon. The entry of exterior airborne particulate lead around the loose-fitting windows of older homes appears possible.

Metabolism of airborne particulate lead in continuously exposed rats: Effect of penicillamine on mobilization

Sprague-Dawley rats of both sexes were exposed to airborne particulate lead at a level of about 20 μg/m3 for periods up to 15 months. Blood lead plateaued at a level of about 26 μg/100 ml within 5 months, as compared to a nearly constant level of 4 μg/100 ml in the controls. On discontinuance of the exposure, the blood lead fell (within 3 months) to a level of about 6 μg/100 ml; treatment with penicillamine (20 mg/kg, twice daily, 5 days per week for 6 weeks) greatly accelerated the rate of decline of this parameter. Urinary and fecal outputs of lead (as micrograms/day) in the treated animals during the exposure period exceeded those in the controls by about 100–300%. There was little increase in tissue lead between the sixth and fifteenth months of exposure; however, in femur the increase during this period was nearly 70%. The level of exposure in these experiments, in terms of micrograms per cubic meter of air far exceeded the yearly mean in most American cities (1–3 μg/m3).

The Accurate Measurement of Lead in Airborne Particulates

Abstract The accurate and rapid measurement of lead in airborne particulates is discussed with particular reference to so-called high-volume air samples. By standard addition analysis, it was found that there is no significant matrix error in measurements of lead taken on glass high-volume filters, within the range of concentrations investigated. This applies to varying or fixed amounts of the glass filter matrix. Recovery of standard added lead is quantitative. Although glass fibre sheet is much too impure for the analysis of most airborne metals, it is possible to analyze lead since the blank is reasonably uniform and since the amounts of lead on such a filter are large in comparison to the blank. Some additional corroboration has been obtained that the distribution of lead is uniform across the total exposed area of the filter. The final error of the lead measurement, as reported, is likely to be more largely a function of sampling problems such as time and flow measurements and particulate fall off and disturbance in sampling, transit and storage.