History and exam

Key diagnostic factors

common

presence of risk factors

Key risk factors include age 9 to 36 months, housing with lead hazards, low socioeconomic status, lead-contaminated water supplies, mineral-deficient and high-fat diets, occupational lead exposure, hobbies working with lead, and fetal lead exposure.

family history of lead poisoning or parental work with lead

Several children in a family often have common exposures.

Housing is the most common source, but lead workers can also bring lead home on clothing.[50] However, in individual cases there may be a requirement to explore uncommon or rare sources of lead exposure.[62]

cognitive impairment (children)

Damage to the central nervous system by lead in children manifests with cognitive impairment as measured by IQ testing. This can lead to learning difficulties and delay in the achievement of developmental milestones.

behavioural changes (children)

Lead-mediated central nervous system (CNS) damage can produce hyperactive and inattentive behaviour.

uncommon

headaches (children)

Precedes the development of lead encephalopathy in children.

clumsiness and agitation (children)

Precedes the development of lead encephalopathy in children.

loss of appetite (children)

Precedes the development of lead encephalopathy in children.

constipation (children)

Precedes the development of lead encephalopathy in children.

somnolence (children)

Precedes the development of lead encephalopathy in children.

altered mental state

Sign of lead encephalopathy, which is a medical emergency.

cerebellar signs

Sign of lead encephalopathy, which is a medical emergency.

seizures

Late sign of lead encephalopathy, which is a medical emergency.

coma

Late sign of lead encephalopathy, which is a medical emergency.

Other diagnostic factors

common

colicky abdominal pain (adults)

Lead toxicity should be suspected in any adult patient with unexplained persistent colicky pain and a high risk of lead exposure.

uncommon

hypertension (adults)

Lead toxicity should be suspected in any adult hypertensive patient with a high risk of lead exposure. Agency for Toxic Substances and Disease Registry: case studies in environmental medicine: lead toxicity Opens in new window

Risk factors

strong

age 9 to 36 months

In the US and other developed countries, the major risk to children is from lead-based paints, and soil and dust contaminated with lead-based paint. Secondary sources include lead jewellery, toys, and other lead items.

Lead in household objects and toys is a considerable concern because they may present a hazard to children. Lead levels in children usually increase during the period of hand-to-mouth activity (ages 9 to 36 months) due to the nature of these sources.[1] Blood lead levels in children peak at age 18 to 24 months.[6]

housing with lead hazards

The primary source of home lead exposure is lead-based paints and dust and soil contaminated by lead-based paints.[6]

Lead hazards are primarily seen in houses built before 1950 and in houses that have deteriorated painted surfaces.

occupational lead exposure

People who work in certain industries (e.g., battery production, heavy construction, mining, automotive repair, metal/electronic recycling) are at high risk of exposure to airborne lead.[12]

Small-business workers such as painting contractors and plumbers are also at risk.[9][13]​​

lead-contaminated water supplies

Lead pipes and lead-soldered copper pipes present a significant risk for exposure when acidic (aggressive) water sits in contact with the lead.[17]

The lead content in the water supply declines significantly with running water and with increasing pH. In most developed countries, using lead solder in home and commercial building water supplies is not allowed, and lead supply pipes generally are being replaced.[18][19][20]

low socioeconomic status

People living in poverty are more likely to live in older and less well-maintained housing with deteriorating lead-based painted surfaces. The combination of old housing and poor quality of housing, both predicted by poverty, increases risk of lead exposure.[6]

hobbies working with lead

Certain hobbies such as constructing stained glass items that are soldered with lead materials, and making bullets and fishing sinkers in the home, often expose the hobbyist to high levels of airborne lead.[6][13]

Self-renovation of an older property may also result in exposure to airborne lead.[6][13]

pica

A medical disorder characterised by an appetite for non-nutritive substances. If the substances consumed contain lead, this may be a significant source of lead exposure.[39][40]

Pica is strongly associated with iron deficiency, which is believed to drive the abnormal appetite.

weak

use of folk medications

Mexican folk remedies (e.g., azarcon and greta), pay-loo-ah (a Hmong folk remedy), and Ayurvedic medicines have resulted in lead toxicity.[10][11][15][16]

A detailed list of exposure sources is available from the US Centers for Disease Control and Prevention (CDC).[6]

fetal exposure

Maternal lead stores are mobilised to the fetus during pregnancy. This mobilisation is a risk factor for fetal loss and subsequent neurological impairment in the infant after delivery.[21]

mineral-deficient and high-fat diets

Diets low in minerals, especially calcium and iron, or high in fat, likely increase absorption of lead.[6][23][33] Pre-existing iron deficiency and other mineral deficiencies also increase the absorption of lead from the gastrointestinal tract.[23]

bullet firing ranges

Lead exposure occurs due to inhalation of airborne lead or lead contamination of clothing and other objects. It is primarily a risk for instructors and others working in the range.

Exposure can be limited by good air exchange and filtration, appropriate use of protective clothing, and restrictions on eating and drinking in the range.[14]

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