Health and Safety
Executive / Commission
Statistics
Lead poisoning is a medical condition caused by excessive exposure to and absorption of lead. Symptoms of lead poisoning are varied and can occur in other medical conditions. Exposure to lead can lead to a range of medical problems, which is why a regime of surveillance of workers in lead industries is under taken here. The vast majority of individuals with blood leads above the suspension level and who are suspended from lead work do not have lead poisoning, but they are removed from further exposure to lead to prevent them developing the condition.
HSE are committed to reducing the exposure of lead and lead-based products to the workforce.
The numbers of workers under survelliance measures the extent of potential led exposure in the national population. The following section looks at the employment levels in the lead working industry since 1996; splitting the workforce by gender.
Figure 1 shows the distribution of the total number of lead workers under medical surveillance.
The total number of workers under medical surveillance in 2006/07 rose slightly to 8,697 persons, after eight consecutive years of decline; although the number of lead workers under surveillance has been on a downward trend since its peak of 26,700 in 1990/91. Of these 8,697 persons, 8,376 (96%) were males and 321 (4%) were females. The total number of workers under surveillance in 2005/06 was 8,618.
The total number of young people (under 18 years) under surveillance (0.05% of workforce) was 8; 4 males and 4 females.
Recording the distribution of the overall lead workforce amongst the lead based industries helps identify possible problem industrial sectors, which can be monitored.
Figure 2 shows the breakdown of male lead workers under medical surveillance by industrial sector in 2006/07. The top three were the lead battery industry (22.9%), smelting, refining, alloying and casting (18.0%) and work with metallic lead and lead containing alloys (9.6%) (other processes being a combination of many smaller industries and therefore not included).
For women, the industrial breakdown shows a different pattern from that of males with the work with metallic lead and lead containing alloys sector (22.4%), lead battery sector (19.9%) and the smelting, refining, alloying and casting (17.4%) accounting for the majority of employment in the lead industry in 2006/07.
Since 1998/99, information has been collected on young people (aged under 18 years) under medical surveillance. The number of young people under medical surveillance continues to remain low with 8 individuals in total in 2006/07, a decrease on the previous year 2005/06 of 22 individuals under surveillance. This decrease may look proportionally high, but erratic fluctuations are common in small cohorts.
Workers are given blood tests to monitor the amount of lead absorbed at the workplace. High lead concentrations in the blood can reach dangerous levels if left unmonitored. If the lead concentrations in the worker’s blood reaches or passes the specified levels of concentration, the worker may be suspended from working with lead until the lead concentration reduces naturally.
Figure 3 illustrates how the proportion of male workers with high blood-lead levels has changed over recent years. Three cut-off points are the suspension levels under the 1980 Regulations (70µg/100ml); the suspension levels under the 1998 Regulations (60µg/100ml); and the action levels under the 1998 Regulations (50µg/100ml).
The proportion of men in the highest two categories has remained broadly level between 2001/02 and 2005/06; the 2006/07 figures show a drop in the total level of high blood-lead measurements. In each of these years approximately 1% of male workers had blood-lead levels at or above 60µg/100ml, down from just under 2% in 1998/99 (the first year of the lower suspension levels), and down from over 3% in 1996/97.
In 2006/07, there were 309 (3.7%) males with blood-lead levels at or above 50µg/100ml. 175 were in the lead battery industry; 29 in work with metallic lead and lead containing alloys; 28 in the smelting, refining, alloying and casting industry and 29 in other processes.
Figure 4 shows how the proportion of female workers with high blood-lead levels has changed over the course of time. The graph shows three cut-off points: the suspension levels under the 1980 Regulations (40µg/100ml); the suspension levels under the 1998 Regulations (30µg/100ml); and the action levels under the 1998 Regulations (25µg/100ml).
The proportion of female workers with blood-lead levels at or above 30µg/100ml has fluctuated around the 4% mark from 2000/01 to 2004/05. In the two latest years, this proportion has fallen to around the 2.5% mark. Prior to which it has dropped from a high of 7% in 1996/97.
The number of women with high blood-lead levels is small and so the proportion tends to fluctuate from year to year, making changes over time difficult to interpret.
Of the 14 females with blood-lead levels at or above 25µg/100ml in 2006/07, 10 were in the lead battery industry, 2 in the glass making, 1 in work with metallic lead and lead containing alloys sectors and 1 in other processes.
A worker whose maximum reading is at or above the suspension level will not necessarily be suspended from working with lead; a repeat measurement may be below the level, or in the case of females the worker may not be of reproductive capacity.
Figures 3 and 4 also show the number of workers suspended from work due to high levels of lead in their blood.
In 2006/07, 28 (0.33%) males were suspended from work due to levels of blood lead exceeding 60 µg/100ml. This was a drop from the 60 (0.72%) males suspended in the previous year of 2005/06.
Only 1 (0.31%) female (the same as in the previous year; although the percentage of female workers was 0.29%) was suspended due to blood lead levels exceeding 30 µg/100ml. The numbers of female workers involved are small and tend to fluctuate from year to year.
Neither the number of workers with measurements over the suspension level nor the number suspended should be interpreted as the number of lead poisonings, the purpose of the arrangements under the Control of Lead at Work (CLAW) regulations is to remove workers from exposure to lead before any toxic effects can occur.