Assessment of cortisol secretory pattern in workers chronically exposed to ELF-EMF generated by high voltage transmission lines and substation

{
  "publication_year": 2022,
  "study_type": "cohort",
  "exposure": {
    "band": "ELF",
    "source": "occupational",
    "frequency_mhz": 5e-05,
    "sar_wkg": null,
    "duration": "Chronic exposure for 1–20 years; personal monitoring day and night for 7 days"
  },
  "population": "Male workers in extra-high voltage (EHV) substations (mean age 38.0 ± 0.9 years) and age-matched unexposed controls",
  "sample_size": 29,
  "outcomes": [
    "Serum cortisol concentrations",
    "Cortisol secretory pattern (including peak-time levels)"
  ],
  "main_findings": "In a comparison between controls (n=15) and workers grouped by magnetic field exposure (0.1–0.3 µT, n=5; >0.3 µT, n=9), the authors report a significant effect of field intensity on the cortisol secretory pattern. The study reports a decline in peak-time serum cortisol concentration in chronically exposed workers.",
  "effect_direction": "harm",
  "limitations": [
    "Small sample size (14 exposed workers)",
    "Only men were studied",
    "Exposure assessment reported for one week, while exposure history spans 1–20 years",
    "Outcome sampling limited to overnight period (20:00–08:00)",
    "Potential confounding factors are not described in the abstract"
  ],
  "evidence_strength": "low",
  "confidence": 0.78,
  "peer_reviewed_likely": "yes",
  "stance": "concern",
  "stance_confidence": 0.74,
  "summary": "This study examined whether chronic occupational exposure to 50 Hz ELF-EMF in extra-high voltage substation workers is associated with changes in cortisol secretion. Personal magnetic-field measurements over seven days (geometric mean 0.1–2.6 µT) were used to classify exposure, and hourly blood samples were collected overnight. Compared with age-matched controls with much lower exposure, field intensity was reported to significantly affect cortisol secretory pattern, including a decline in peak-time cortisol in exposed workers.",
  "key_points": [
    "The study evaluated 50 Hz ELF-EMF exposure in 14 male EHV substation workers with 1–20 years of exposure history.",
    "Magnetic field exposure was measured with Emdex dosimeters worn day and night for seven days, with a one-week geometric mean of 0.1–2.6 µT.",
    "Controls (n=15) were age-matched and reported to have exposure levels ten times lower than workers.",
    "Blood was sampled hourly from 20:00 to 08:00 to assess overnight cortisol secretion patterns.",
    "Cortisol secretory pattern differed by exposure intensity when comparing controls to workers exposed to 0.1–0.3 µT and >0.3 µT.",
    "The authors report a decline in peak-time cortisol concentration in chronically exposed workers and call for further studies in high-risk populations."
  ],
  "categories": [
    "Occupational Exposure",
    "Power Lines & Substations",
    "Endocrine Effects",
    "ELF (Extremely Low Frequency)"
  ],
  "tags": [
    "ELF-EMF",
    "50 Hz",
    "Occupational Exposure",
    "Extra-High Voltage Substation",
    "High-Voltage Transmission Lines",
    "Magnetic Field Dosimetry",
    "Emdex Dosimeter",
    "Cortisol",
    "HPA Axis",
    "Circadian Rhythm",
    "Chronic Exposure"
  ],
  "keywords": [
    "extremely-low frequency electromagnetic fields",
    "ELF-EMF",
    "50 Hz",
    "extra-high voltage substations",
    "high voltage transmission lines",
    "magnetic field strength",
    "dosimeter",
    "Emdex",
    "cortisol",
    "secretory pattern",
    "hypothalamic-pituitary-adrenal axis",
    "chronic exposure"
  ],
  "suggested_hubs": [
    {
      "slug": "occupational-exposure",
      "weight": 0.86,
      "reason": "Study population is workers in extra-high voltage substations with chronic occupational ELF-EMF exposure."
    },
    {
      "slug": "power-lines",
      "weight": 0.8,
      "reason": "Exposure source includes high-voltage transmission lines and substations."
    }
  ],
  "social": {
    "tweet": "Study of 14 EHV substation workers (50 Hz ELF-EMF) with 1–20 years exposure found field intensity was linked to altered overnight cortisol secretion patterns, including reduced peak-time cortisol vs age-matched controls. More research in high-risk groups was recommended.",
    "facebook": "Researchers measured 50 Hz ELF-EMF exposure in extra-high voltage substation workers and collected hourly overnight blood samples. Compared with age-matched controls, exposure intensity was reported to significantly affect cortisol secretion patterns, including reduced peak-time cortisol in chronically exposed workers.",
    "linkedin": "In an occupational study of extra-high voltage substation workers, personal 50 Hz magnetic-field monitoring (0.1–2.6 µT geometric mean over 7 days) and hourly overnight blood sampling suggested exposure intensity was associated with changes in cortisol secretory pattern, including reduced peak-time cortisol vs controls. Further studies were recommended."
  }
}