Independent, modified, and interacting effects of long-term noise, extremely low-frequency electromagnetic fields, and shift work exposures on liver enzymes

Environmental pollution (Barking, Essex : 1987) · 2023 · Harm · Low evidence

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HarmLow evidencePaper 453

Study snapshot

PublicationEnvironmental pollution (Barking, Essex : 1987) · 2023

Study typecohort

Reported directionHarm

Evidence ratingLow

Abstract

Independent, modified, and interacting effects of long-term noise, extremely low-frequency electromagnetic fields, and shift work exposures on liver enzymes Khosravipour M, Ghanbari Kakavandi M, Gharagozlou F, Nadri F, Barzegar A, Emami K, Valadi Athar H. Independent, modified, and interacting effects of long-term noise, extremely low-frequency electromagnetic fields, and shift work exposures on liver enzymes. Environ Pollut. 2023 Jun 13:122036. doi: 10.1016/j.envpol.2023.122036. Abstract To quantify long-term independent, modified, and interacting effects of noise, extremely low-frequency electromagnetic fields (ELF-EMFs), and shift work exposures on liver enzymes, a four-year repeated measures study was performed among male workers in a thermal power plant industry from 2016 to 2020. The 8-h equivalent sound pressure levels (Leq) were measured at weighting channels of Z, A, and C for octave-band frequencies. The 8-h time-weighted average of ELF-EMFs levels was measured for each participant. Shift work schedule was determined based on job titles, including 3-rotating night shift work and fixed day shift work schedules. The fasting blood samples were taken to determine liver enzymes (AST, Aspartate transaminase; ALT, Alanine transaminase). The percentage change (PC) and 95% confidence interval (CI) of AST and ALT enzymes were estimated by the different bootstrapped-mixed-effects linear regression models. Per 10-dB noise increase, we found a significantly higher PC (95% CI) of AST and ALT (only LAeq) levels in all regression models with the highest changes for LAeq. For octave-band noise analysis, there was an upward trend from 31.5 Hz to 1 kHz frequencies and a downward trend from 1 to 8 kHz frequencies. Per 1 mG ELF-EMFs increase, we observed a significantly higher PC (95% CI) of AST and ALT enzymes in the main adjusted and main adjusted + shift work models. 3-rotating night than fixed day shift workers had a significant PC in the unadjusted model for AST enzyme and the fully adjusted and main adjusted + ELF-EMFs for ALT enzyme. Significant negative two-way or/and three-way interaction effects among the noise, ELF-EMFs, and shift work were observed for both AST and ALT enzymes. Our findings indicated long-term noise, ELF-EMFs, and 3-rotating night shift work exposures may be significantly associated with changes in the levels of liver enzymes. pubmed.ncbi.nlm.nih.gov

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AI evidence extraction

Structured fields below were generated from the paper’s abstract and metadata to make the evidence easier to inspect. Automated extraction may be incomplete or incorrect; verify important details against the original paper.

Study typecohort

Effect directionharm

PopulationMale workers in a thermal power plant industry

Sample sizeNot supplied

ExposureELF · long-term; 4-year repeated measures (2016–2020); 8-h time-weighted average ELF-EMFs

Evidence strengthLowConfidence: 74% · Peer reviewed: yes

Main findings

In bootstrapped mixed-effects linear regression models, per 10-dB noise increase was associated with significantly higher percentage change in AST and ALT (ALT only for LAeq) across models, with the highest changes for LAeq. Per 1 mG increase in ELF-EMFs, AST and ALT showed significantly higher percentage change in the main adjusted and main adjusted + shift work models. Shift work (3-rotating night vs fixed day) showed significant percentage changes for AST in the unadjusted model and for ALT in fully adjusted and main adjusted + ELF-EMFs models; significant negative two-way and/or three-way interaction effects among noise, ELF-EMFs, and shift work were reported for both enzymes.

Outcomes measured

AST (aspartate transaminase)
ALT (alanine transaminase)

View raw extracted JSON

{
  "study_type": "cohort",
  "exposure": {
    "band": "ELF",
    "source": "occupational",
    "frequency_mhz": null,
    "sar_wkg": null,
    "duration": "long-term; 4-year repeated measures (2016–2020); 8-h time-weighted average ELF-EMFs"
  },
  "population": "Male workers in a thermal power plant industry",
  "sample_size": null,
  "outcomes": [
    "AST (aspartate transaminase)",
    "ALT (alanine transaminase)"
  ],
  "main_findings": "In bootstrapped mixed-effects linear regression models, per 10-dB noise increase was associated with significantly higher percentage change in AST and ALT (ALT only for LAeq) across models, with the highest changes for LAeq. Per 1 mG increase in ELF-EMFs, AST and ALT showed significantly higher percentage change in the main adjusted and main adjusted + shift work models. Shift work (3-rotating night vs fixed day) showed significant percentage changes for AST in the unadjusted model and for ALT in fully adjusted and main adjusted + ELF-EMFs models; significant negative two-way and/or three-way interaction effects among noise, ELF-EMFs, and shift work were reported for both enzymes.",
  "effect_direction": "harm",
  "limitations": [],
  "evidence_strength": "low",
  "confidence": 0.74,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "extremely low-frequency electromagnetic fields",
    "ELF-EMFs",
    "occupational exposure",
    "thermal power plant",
    "noise",
    "shift work",
    "night shift",
    "liver enzymes",
    "AST",
    "ALT",
    "repeated measures",
    "mixed-effects regression",
    "interaction effects"
  ],
  "suggested_hubs": [
    {
      "slug": "occupational-exposure",
      "weight": 0.9,
      "reason": "Study population is male workers in a thermal power plant with measured 8-h time-weighted average ELF-EMFs and noise exposures."
    }
  ]
}

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AI-extracted fields are generated from the abstract and metadata and may be incomplete or incorrect. This material is for informational purposes and is not medical advice.

Identifiers and source

DOI: 10.1016/j.envpol.2023.122036
PubMed: 37321317

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