Exposure to lead

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 lead levels 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 the workforce to lead and lead-based products.

Summary

• The report covers blood lead measurements taken over the period from 1st April 2007 to 31st March 2008.
• The total number of workers under medical surveillance in 2007/08 fell to 8,069 from the 8,697 of 2006/07. Of these 8,069 persons, 7,752 (96%) were male and 317 (4%) were female.
• There were 7 young people (under 18 years) under surveillance in 2007/08; all of which were male.
• Three industry sectors account for the majority of males working with lead, these being smelting, refining, alloying and casting (17.2%), the lead battery industry (14.4%)  and manufacture of inorganic and organic compounds (9.4%).
• The three industry sectors that account for the majority of females working with lead are the lead battery sector (24.9%), the metallic lead and lead containing alloys sector (22.1%) and the smelting, refining, alloying and casting sector (13.9%)
• The proportion of male workers with blood-lead measurements at or above the 60µg/100ml level has dropped from around 1% in 2006/07 to 0.5% in 2007/08 of the total male workforce. There were 248 (3.2%) individuals recorded to have a blood lead measurement above the recommended action level of 50µg/100ml.
• Since 2006/07 the proportion of female workers with blood-lead levels at or above 30µg/100ml has fallen to 1.3% of the total female workforce. There were 12 females (3.8%) who were recorded to have a blood lead measurement above the 25µg/100ml recommended action level.
• In 2007/08, a total of 29 males were suspended from work due to levels of blood lead exceeding 60 µg/100ml. No females were suspended due to blood lead levels exceeding 30 µg/100ml.

Workforce under medical surveillance

The numbers of workers under surveillance measures the extent of potential lead 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.

The total number of workers under medical surveillance in 2007/08 fell slightly to 8,069 persons, the number of lead workers under surveillance has been on a downward trend since its peak of 26,700 in 1990/91. Of these 8,069 persons, 7,752 (96%) were males and 317 (4%) were females. The total number of workers under surveillance in 2006/07 was 8,697.

The total number of young people (under 18 years) under surveillance was 7; all of which were male.

More Information on lead working regulations can be found at:

• Surveillance of workers exposed to lead
• HSE Lead website

Lead based industry distribution

Recording the distribution of the overall lead workforce amongst the lead based industries helps identify possible problem industrial sectors, which can be monitored. A number of assessments (4.4%) had no recorded sector code, these are included for completeness under the title “Missing Sector Information”.

The top three industry sectors were smelting, refining, alloying and casting (17.2%), the lead battery industry (14.4%) and manufacture of inorganic and organic compounds (9.4%) (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 work within the lead battery sector (24.9%), work with metallic lead and lead containing alloys (22.1%) and the smelting, refining, alloying and casting sector (13.9%) accounting for the majority of employment in the lead industry in 2007/08.

Since 1998/99, separate 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 7 individuals in total in 2007/08, a slight decrease on the previous year 2006/07 of 8 individuals under surveillance.  One individual worked in the lead battery sector, three painted buildings or vehicles, two worked in other smaller industries and one had no sector information.

Blood lead levels in workers

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. The figures shown here are those of the workers’ with the highest blood-lead level readings.

Three cut-off points are shown, representing the suspension levels under the 1980 Regulations (70µg/100ml); the suspension levels under the 1998/2002 Regulations (60µg/100ml); and the action levels under the 1998/2002 Regulations (50µg/100ml). Young males have a suspension level of 50µg/100ml and an action level of 40µg/100ml; no individuals were recorded with these exposures.

The proportion of men in the highest two categories has remained broadly level between 2001/02 and 2005/06; the figures for 2006/07 to 2007/08 show a drop in the total level of high blood-lead measurements. In  2007/08 approximately 0.5% of male workers had blood-lead levels at or above 60µg/100ml, down from 1% in 2006/2007, 2% in 1998/99 (the first year of the lower suspension levels), and down from over 3% in 1996/97.

In 2007/08, there were 248 (3.2%) males with blood-lead levels at or above 50µg/100ml. The four industry sectors with the majority of the highest blood-lead level readings were: manufacture of inorganic and organic compounds accounted for 66 individuals, 45 were in the lead battery industry, 28 were employed in the glass making sector and 29 in other processes.

The graph shows three cut-off points: the suspension levels under the 1980 Regulations (40µg/100ml); the suspension levels under the 1998/2002 Regulations (30µg/100ml); and the action levels under the 1998/2002 Regulations (25µg/100ml).

In 1996/97 the proportion of female workers with blood-lead levels at or above 30µg/100ml was at a high of 7%. It then fell and fluctuated around the 4% mark from 2000/01 to 2004/05. In the last two  years, this proportion has fallen further to around the 2.5% mark.

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 12 females with blood-lead levels at or above 25µg/100ml in 2007/08, 10 were in the lead battery industry, 1 in the glass making 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.

Suspensions

Figures 4 and 5 also show the proportion of workers suspended from work due to high levels of lead in their blood.

In 2007/08, 29 (0.37%) males were suspended from work due to levels of blood lead exceeding 60 µg/100ml. This was a slight rise from the 28 (0.33%) males suspended in the previous year of 2006/07. These 29 individuals were suspended a total of 34 times in the year 2007/08.

No females  were 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.