Influence of Electromagnetic Fields on Lead Toxicity: A Study of Conformational Changes in Human Blood Proteins.

Abstract

BACKGROUND: Electromagnetic fields (EMF) are associated with oxidative stress, which is in turn associated with reactive oxygen species (ROS), anemia, and hypoxia. OBJECTIVES: This study focused on the synergistic effects of lead ions and EMF on oxidative modifications in hemoglobin (Hb) and plasma proteins. PATIENTS AND METHODS: In this experimental study, the blood samples were obtained from age- and sex-matched healthy subjects at Arak University of Medical Sciences, Arak, Iran. The collected bloods were prepared as 55 samples and then divided into different groups for incubating with 0 to 100 uM of lead ions in 2 mT and 50 Hz of EMF for 120 minutes. The carbonyl group was determined to be an oxidative biomarker in plasma proteins. The ferric reducing ability of plasma (FRAP) was considered to be an antioxidant power of human plasma. The conformational changes in hemoglobin, met-Hb, and hemichrome were considered to be oxidative markers in red blood cells. To predict the factors affecting the oxyHb, the artificial neural network (MLP: 11,2,2,1) in SPSS software was applied. RESULTS: The test subjects showed increased concentrations of metHb (1.8 ± 0.19 vs. 1.36 ± 0.25) and hemichrome (6.01 ± 0.57) in relation to the control subjects. The decreased absorbance at 340 nm (0.88 ± 0.09 vs. 1.07 ± 0.08) demonstrated the reduced interaction between the globin chain and the heme ring. The decreased absorbance at 420 nm (Soret band) (2.96 ± 0.13) and the increased absorbance at 630 nm (0.07 ± 0.002 vs. 0.064 ± 0.005) indicated the conversion of oxyHb to metHb, which confirmed the oxidative damage to the erythrocytes. The linear regression analysis showed significant positive correlations between lead concentration and the percentage of plasma carbonyl content (R2 = 0.96), the relation of plasma carbonyl content to Hb absorbance at 630 nm (R2 = 0.97), and the relation of plasma carbonyl content to metHb concentration (R2 = 0.95) after 120 minutes incubation with lead ions in 20 millitesla and 50 hertz EMF. The artificial neural network analysis showed the significant importance of hemichrome, PCO, metHb, and lead concentration to the oxyHb content of erythrocytes. CONCLUSIONS: Lead contamination in the presence of an EMF exacerbates the oxidative damage to plasma proteins as well as the conformational changes in Hb. An artificial neural network can be used as a predictive tool for the oxidative danger posed to workers in industrial fields, battery manufacturing companies, and power plants.

AI evidence extraction

Main findings

In incubated human blood samples, exposure conditions involving lead ions with ELF-EMF were associated with increased metHb and hemichrome and absorbance changes consistent with oxidative damage to erythrocytes. Regression analyses reported strong positive correlations between lead concentration and plasma carbonyl content, and between plasma carbonyl content and Hb oxidative markers after 120 minutes incubation with lead ions in EMF.

Outcomes measured

• Oxidative modifications in hemoglobin (oxyHb to metHb conversion)
• methemoglobin (metHb) concentration
• hemichrome concentration
• Hemoglobin absorbance changes (340 nm, 420 nm/Soret band, 630 nm)
• Plasma protein carbonyl content (oxidative biomarker)
• Ferric reducing ability of plasma (FRAP; antioxidant power)
• Conformational changes in hemoglobin and plasma proteins

Limitations

• Experimental in vitro incubation study using collected blood samples; findings may not directly translate to in vivo health outcomes.
• EMF intensity reported inconsistently (2 mT in methods vs 20 mT in results).
• Details of group assignments and results for all lead concentrations (0–100 µM) are not fully described in the abstract.

Suggested hubs

• occupational-exposure (0.6)
  Conclusion discusses relevance to workers in industrial fields, battery manufacturing, and power plants (lead plus EMF exposure context).

{
    "study_type": "in_vitro",
    "exposure": {
        "band": "ELF",
        "source": "other",
        "frequency_mhz": 0.05000000000000000277555756156289135105907917022705078125,
        "sar_wkg": null,
        "duration": "120 minutes incubation"
    },
    "population": "Blood samples from age- and sex-matched healthy subjects (Arak University of Medical Sciences, Iran)",
    "sample_size": 55,
    "outcomes": [
        "Oxidative modifications in hemoglobin (oxyHb to metHb conversion)",
        "methemoglobin (metHb) concentration",
        "hemichrome concentration",
        "Hemoglobin absorbance changes (340 nm, 420 nm/Soret band, 630 nm)",
        "Plasma protein carbonyl content (oxidative biomarker)",
        "Ferric reducing ability of plasma (FRAP; antioxidant power)",
        "Conformational changes in hemoglobin and plasma proteins"
    ],
    "main_findings": "In incubated human blood samples, exposure conditions involving lead ions with ELF-EMF were associated with increased metHb and hemichrome and absorbance changes consistent with oxidative damage to erythrocytes. Regression analyses reported strong positive correlations between lead concentration and plasma carbonyl content, and between plasma carbonyl content and Hb oxidative markers after 120 minutes incubation with lead ions in EMF.",
    "effect_direction": "harm",
    "limitations": [
        "Experimental in vitro incubation study using collected blood samples; findings may not directly translate to in vivo health outcomes.",
        "EMF intensity reported inconsistently (2 mT in methods vs 20 mT in results).",
        "Details of group assignments and results for all lead concentrations (0–100 µM) are not fully described in the abstract."
    ],
    "evidence_strength": "low",
    "confidence": 0.7399999999999999911182158029987476766109466552734375,
    "peer_reviewed_likely": "yes",
    "keywords": [
        "electromagnetic fields",
        "ELF-EMF",
        "50 Hz",
        "millitesla",
        "lead ions",
        "oxidative stress",
        "reactive oxygen species",
        "hemoglobin",
        "methemoglobin",
        "hemichrome",
        "plasma protein carbonyls",
        "FRAP",
        "in vitro",
        "blood proteins",
        "artificial neural network"
    ],
    "suggested_hubs": [
        {
            "slug": "occupational-exposure",
            "weight": 0.59999999999999997779553950749686919152736663818359375,
            "reason": "Conclusion discusses relevance to workers in industrial fields, battery manufacturing, and power plants (lead plus EMF exposure context)."
        }
    ]
}

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