This narrative review examined the effects of key airborne metals (arsenic, cadmium, chromium, copper, lead, mercury, manganese, nickel, vanadium, and zinc) on vulnerable populations, analyzing articles published over the past decade. The review covers inhalation toxicokinetics, molecular toxicity mechanisms, and population-specific susceptibilities. Articles published in the past 10 years were included; focus was on human health effects.
Key numbers
- Ambient air arsenic concentrations have been reported to range from 0.800 to 15.7 ng/m3, sometimes exceeding permissible limits.
- Arsenic OSHA permissible exposure limit (PEL): 0.01 mg/m3; NIOSH recommended exposure limit (REL): 0.002 mg/m3.
- Arsenic toxicity mechanisms in Table 1: thiol binding and inhibition of thiol-rich enzymes (pyruvate dehydrogenase, 2-oxoglutarate dehydrogenase, tyrosine phosphatases); interaction with zinc finger proteins; interaction with tubulin (mitotic arrest); altered MAPKs, NF-kappaB; uncoupled oxidative phosphorylation (altered ATP production).
- Arsenic lung pathogenesis disorders (Table 1 from companion paper cited): irritation of nasal mucosa, larynx, bronchi; perforation of nasal septum; rhino-pharyngolaryngitis; trachea bronchitis; pulmonary insufficiency; chronic cough; bronchopulmonary disease; arsenic bronchitis; asthma; dyspnea; non-cardiogenic pulmonary edema; increased capillary permeability; lung cancer.
- In a mouse model, in utero exposure to arsenic impaired lung development, resulting in changes in respiratory function in postnatal pups.
- Prenatal and postnatal exposure to arsenic in air-polluted areas shown to harm lungs, causing a restrictive pattern that decreases lung volume.
- PM contains metals predominantly in fine and ultrafine particles: PM10 (greater than 2.5-10 µm), PM2.5 (less than 2.5 µm), and PM0.1 (less than 0.1 µm, ultrafine, capable of reaching alveoli and bloodstream).
Methods (brief)
Narrative review; PubMed, Scopus, Web of Science, Google Scholar search; studies published in the past decade; human health effects on vulnerable populations; emphasis on airborne (inhalation) exposure routes. Non-English language studies, articles without full text, and publications unrelated to heavy metals exposure or human health were excluded.
Evidence fitness
Supports: inhalation toxicology of arsenic and other metals, particularly in vulnerable populations (pregnant women, children, elderly); provides ambient air concentration context and regulatory exposure limits. Limitation: narrative (not systematic); primarily inhalation exposure, not dietary; heterogeneous study quality across citations.
Limitations
Narrative review (not systematic or meta-analytic); inhalation-primary focus (not dietary exposure); vulnerable population susceptibility data largely from animal models or mechanistic studies; some conclusions extrapolated from occupational to environmental exposures.
Related evidence
- Arsenic exposure and respiratory outcomes
- Vulnerable populations and metal exposure
- Arsenic, Inorganic
Update history
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