| Health Impacts | Exposure to lead-related pollution can adversely affect mental development and performance, kidney function, and blood chemistry. This is particularly a risk for young children, due to the increased sensitivity of young tissues and organs. Common symptoms observed in children include IQ loss, reading and learning difficulties, hearing loss, hyperactivity and difficulties in concentration. Lead-related pollution also causes cardiovascular problems in adults, even with low levels of exposure. Adverse reproductive effects in women have also been observed. Finally, fetal exposure can result in reduced birth weight, infant mortality, and fetal deaths. The health impacts of airborne lead pollution are highly dependent on the levels and distribution patterns of the pollution, as well as on the features of the population exposed (e.g., age and health conditions). The influence of other local characteristics, such as building height, distance from intensive road traffic, and the existence of stationary lead sources should also be considered.
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| Blood Lead Levels (BLL) | The key indicator of exposure is the Blood Lead Level (BLL). Although the US Center for Disease Control and Prevention (CDC) revised its intervention threshold for the blood lead level from 25 µg/dl to 10 µg/dl (Center for Disease Control and Prevention, 1991), recent studies have indicated that, depending on the individual sensitivity to lead-induced neurotoxicity and individual susceptibility, even a Blood Lead Level below 10 µg/dl can lead to negative neuro-motoric and neurobehavioral effects in older children (Grandjean, 1993). Recent research in Slovakia (E. Sovcikova, 1996) has revealed subtle changes in the neuromotor and cognitive performance of older children with a BLL lower than 10 µg/dl. Significantly worse performance was found in fundamental functions (such as lower psychical activity and slowed reaction time), and in the overall levels of intelligence. Data on the concentration of lead in ambient air, and on the blood lead levels as an indicator of the health impact from lead air pollution are presented in Tables 2 and 3, respectively. The tables provide comprehensive data for different groups of people.
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| TABLE 2: Concentration of Lead in Ambient Air | ||||||||
|---|---|---|---|---|---|---|---|---|
| Country | City or area | Lead concentration in ambint air (µg/m3) | ||||||
| 1990 | 1991 | 1992 | 1993 | 1994 | 1995 | 1996 | ||
| Bulgaria | Sofia | 0.3 | 0.3 | 0.3 | 0.3 | 0.2 | 0.2 | |
| Pernik | 0.5 | 0.4 | 0.4 | 0.2 | 0.2 | 0.4 | ||
| Plovdiv | 0.6 | 0.5 | 0.4 | 0.3 | 0.2 | 0.3 | ||
| Kardjali | 1.2 | 1.2 | 1.2 | 0.9 | 0.9 | 0.7 | ||
| Czech Republic1 | Prague | 0.055 | 0.042 | 0.014 | ||||
| Pribram | 0.078 | 0.059 | 0.017 | |||||
| Usti n. Labem | 0.058 | 0.040 | 0.027 | |||||
| Brno | 0.069 | 0.082 | 0.045 | |||||
| Ostrava | 0.050 | 0.081 | 0.046 | |||||
| Hungary | Budapest | 0.20 | 0.22 | 0.22 | 0.19 | |||
| Pecs | 0.42 | 0.44 | 0.25 | 0.21 | ||||
| Miskolc | 0.18 | 0.12 | ||||||
| Debrecen | 0.56 | 0.30 | 0.27 | 0.28 | ||||
| Poland2 | Katowice | 0.730 | 0.900 | 1.160 | 1.160 | 0.684 | 0.780 | 0.577 |
| Chorzuw | 2.690 | 0.850 | 0.760 | 0.940 | 0.443 | 0.812 | 0.995 | |
| Pszczyna | 0.640 | 0.550 | 0.450 | 0.460 | 0.489 | 0.617 | 0.162 | |
| Lodz | - | 1.162 | 1.478 | 0.855 | 0.867 | 1.847 | 0.552 | |
| Romania | Copsa Mica | 30.30 | 21.30 | 16.07 | 42.20 | 18.91 | 12.70 | |
| Bucuresti | 60.58 | 60.58 | 70.65 | 7.63 | ||||
| Bala Mare | 5.45 | 8.20 | 97.50 | 15.07 | 16.12 | 13.34 | ||
| Medias | 10.15 | 21.80 | 7.20 | 4.18 | 9.99 | 14.70 | ||
| Zlatna | 22.72 | 27.10 | 10.00 | 14.00 | 9.44 | 11.46 | ||
| Slovakia | Bratislava | 0.114 | 0.091 | 0.112 | 0.101 | 0.053 | 0.058 | |
| B. Bystrica | 0.111 | 0.089 | 0.075 | 0.049 | 0.033 | 0.030 | ||
| Ruzomberok | 0.142 | 0.051 | 0.057 | 0.027 | 0.040 | 0.018 | ||
| Richnava | 0.505 | 0.534 | 0.458 | 0.221 | 0.140 | 0.210 | ||
| Slovenia | Trbovlje | 0.90 | 0.70 | 0.30 | ||||
| Zagorje | 1.50 | 0.70 | 0.30 | |||||
| Hrastnik | 0.25 | 0.45 | 0.10 | |||||
Note: Italicized text denotes short term max. concentration (µg/m3) 1. Source: National Institute of Public Health, annual geometric means, 1996 2. Data from the State Heath Inspectorate (max. average daily concentration) |
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| TABLE 3: Blood Lead Levels in Adults and Children | ||||
|---|---|---|---|---|
| Country | City or area | Year | BLL - mean value (range) [µg/dl] | Groups under examination |
| Bulgaria | Momchilgrad | 1991 | 11.4 | children, 5-7 years old |
| Momchilgrad | 1991 | 11.6 | teenagers, 12-14 years old | |
| Krichim | 1991 | 9.2 | children | |
| Kurtovo Konare | 1991 | 17.0 | children and teenagers | |
| Haskovo | 1995 | 10.1 | children, 5-7 years old | |
| Haskovo | 1995 | 11.4 | teenagers, 11-12 years old | |
| Nationwide | 1995-1996 | 15 | adults | |
| Czech Republic | Pribram | 1992-1994 | 14.66; 6.61; 4.951 | children, 1-3 years old |
| 10.2; 4.95; 4.67 | children, 4-7 years old | |||
| 12.50; 5.37; 4.51 | children, 8-11 years old | |||
| 7.21; 4.84; 4.69 | teenagers, 12-14 years old | |||
| Hungary | Budapest | 1992 | 11.9 | |
| Sopron | 1993 | 11.6 | ||
| local | 1994 | 7.4 | ||
| National | 1995 | 6.26 | ||
| Budapest | 1996 | 6.5 | ||
| Poland | Five towns with no industrial lead emitters | 1992-1994 | 4.25-7.68 2.38-4.83 2.39-6.23 |
males females children |
| Based in the vicinity of zinc and copper mills | 1992-1994 | 9.85-15.90 | males females children |
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| Romania | North Railway Station | 1983-1985 | 17.1 | children |
| (six areas of Bucharest) | Balta Alba | 1983-1985 | 18.40 | children |
| Center | 1983-1985 | 20.20 | children | |
| Giurgiuhu | 1983-1985 | 21.93 | children | |
| Militari | 1983-1985 | 17.84 | children | |
| Pantelimon | 1983-1985 | 20.51 | children | |
| Slovakia | Bratislava | 1993 | 3.65 | children |
| Middle Slovakia | 1995 | 4.5 | children | |
| North Slovakia | 1996 | 3.04 | children | |
1. Geometric mean values [mg/dl] for subjects living at distances from the lead smelter of less than 3 km, 3-5 km, and over 5 km Source: Final Report of the National Integrated Program on Environment and Health Project, 1995 |
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| Declining Lead Concentrations | The data in Table 2 clearly shows a decline in the concentrations of lead in ambient air in the SILAQ countries, with the exception of certain areas in Poland (Pszczyna and Lodz) and in Romania (Baia Mare and Medias). The apparent increase in these cities may be caused by stationary sources. At any rate, it is interesting to note that for both Poland and Romania, the total lead emission levels are significantly higher (even up to one order of magnitude), than those for Hungary and Slovenia (although it is unclear whether the difference may have been caused by different measurement techniques for short term maximum concentrations). Comparison of figures for Bulgaria and Slovakia (which provided data concerning annual mean values rather than short term maximum concentrations) shows that progress in the phase-out of leaded gasoline in Slovakia has resulted in a remarkable decline in airborne lead. In Bulgaria, the average decrease between 1990 and 1995 has been about 30 percent, while in Slovakia it has ranged between 50 percent and 88 percent. In the Czech Republic, a trend in the decline of the ambient air lead concentrations during the period 1993-1995 has been reported in three of the surveyed industrial centers with heavy traffic, namely in Prague, Pribram and Usti n. Labem. It is worth noting that airborne lead concentration limits for ambient air are 1 µg/m3 in Bulgaria, 0.3 µg/m3 in Hungary and 0.5 µg/m3 in Poland. Table 3 reports on the results of investigations of blood lead levels, chiefly in children but also for adults. In Poland, for instance, three groups are distinguished: "males", "females" and "children". For Bulgaria, sex is not distinguished, but rather data is provided for the categories of "children" and "teenagers" as well as "adults."
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| Trends in BLL | Based on the data in Table 3, no firm conclusions can be drawn concerning the BLL trends during a certain period of time for a given area. The only exception is Budapest, where a remarkable decrease of 45 percent in BLL is shown between 1992 and 1996. However, since there is no data available for 1992 levels of airborne lead, this cannot be directly related to airborne lead pollution. The data for Bulgaria shows that the BLLs for both "children" and "teenagers" are almost the same, and range around 11 µg/dl. The highest BLLs have been measured in Romania (17-22 µg/dl). These are 2-5 times higher than those in Bulgaria and Slovakia, respectively, although it should be pointed out that the data for Romania is dated (1983-1985). When comparing BLL data for Bulgaria, Hungary, Poland and Slovakia, it appears that the phase-out of leaded gasoline in Slovakia has had a significant effect on health, since the lowest BLLs are measured there. A recent study carried out in the Czech Republic within the framework of the National Integrated Program on Environment and Health (NIPEH) determined that BLLs are within the range of 6-25 µg/dl for adults and less then 10 µg/dl for children. Levels of 20-30 µg/dl were commonly found in workers in certain industrial sectors. Data on BLLs for children living in the vicinity of a lead smelter in Pribram are presented in Table 3. As a result of lead exposure, significant changes in psychomotorical development of children were observed.
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