Memory loss risk assessment for the students nearby high-voltage power lines-a case study.

Abstract

With increasing sources of alternating current electromagnetic fields (EMFs) in everyday life, their possible harmful effects on human health are a main area of concern in many countries. Given that children are the most valuable assets of each country, it is of utmost importance to study the effect(s) of EMF exposure on various health aspects of members within this age group. The present research is the first systematic study of the effects of exposure to electric substations on the memory status of male students in the age group of 10 to 12 years. The flux density values of extremely low frequency magnetic field were measured at four elementary schools in Tehran in accordance with IEEE std 644-1994. The device was 3-axis (X, Y, and Z) Gauss Meter, model: TES-1394. The students from two schools nearby a high voltage electricity substation (at distances of 30 and 50 m) were selected as the exposed group, and the students of two other schools at further distances of 1390 and 610 m were considered as the control group. To determine the status of working memory in the students, the questionnaire was adapted from Wechsler Intelligence Scale for Children (WISC-IV). The completed questionnaires were analyzed by t test and chi-square using SPSS 20. The average magnetic flux density was 0.245 μT at case schools and 0.164 μT at control schools, P < 0.01. The demographic characteristics of the students in the two groups were not statistically different. However, the difference in working memory was significant at the level of 5 %. The results of the questionnaire data showed that students in the control group had better working memory compared to students in case group. The findings revealed a reverse correlation between magnetic flux density and working memory of students (R = -0.255). It is concluded that extremely low frequency magnetic field exposure may have a negative impact on the working memory of children, but further studies are necessary to reach a definitive conclusion.

AI evidence extraction

Main findings

ELF magnetic flux density measured at two schools near a high-voltage electricity substation (30 and 50 m) averaged 0.245 µT versus 0.164 µT at two control schools farther away (610 and 1390 m; P<0.01). Working memory differed significantly (5% level), with better working memory in the control group; magnetic flux density was inversely correlated with working memory (R = -0.255).

Outcomes measured

• Working memory status (WISC-IV-based questionnaire)
• Magnetic flux density (µT) at schools

Limitations

• Study design appears observational/cross-sectional (no randomization described).
• Sample size not reported in the abstract.
• Exposure characterized by school distance and spot/area measurements; individual-level exposure over time not described.
• Outcome assessed via questionnaire adapted from WISC-IV rather than full clinical/neuropsychological testing (as described).
• Only male students included; generalizability to females not addressed.

Suggested hubs

• occupational-exposure (0.15)
  Exposure assessment near electrical infrastructure; however population is schoolchildren, not workers (hub match is weak).

{
    "study_type": "cross_sectional",
    "exposure": {
        "band": "ELF",
        "source": "high-voltage power lines / electricity substation (nearby schools)",
        "frequency_mhz": null,
        "sar_wkg": null,
        "duration": null
    },
    "population": "Male elementary school students aged 10–12 years in Tehran (Iran)",
    "sample_size": null,
    "outcomes": [
        "Working memory status (WISC-IV-based questionnaire)",
        "Magnetic flux density (µT) at schools"
    ],
    "main_findings": "ELF magnetic flux density measured at two schools near a high-voltage electricity substation (30 and 50 m) averaged 0.245 µT versus 0.164 µT at two control schools farther away (610 and 1390 m; P<0.01). Working memory differed significantly (5% level), with better working memory in the control group; magnetic flux density was inversely correlated with working memory (R = -0.255).",
    "effect_direction": "harm",
    "limitations": [
        "Study design appears observational/cross-sectional (no randomization described).",
        "Sample size not reported in the abstract.",
        "Exposure characterized by school distance and spot/area measurements; individual-level exposure over time not described.",
        "Outcome assessed via questionnaire adapted from WISC-IV rather than full clinical/neuropsychological testing (as described).",
        "Only male students included; generalizability to females not addressed."
    ],
    "evidence_strength": "low",
    "confidence": 0.7800000000000000266453525910037569701671600341796875,
    "peer_reviewed_likely": "yes",
    "keywords": [
        "extremely low frequency",
        "ELF",
        "magnetic flux density",
        "electric substation",
        "high-voltage power lines",
        "children",
        "students",
        "working memory",
        "WISC-IV",
        "Tehran",
        "IEEE std 644-1994"
    ],
    "suggested_hubs": [
        {
            "slug": "occupational-exposure",
            "weight": 0.1499999999999999944488848768742172978818416595458984375,
            "reason": "Exposure assessment near electrical infrastructure; however population is schoolchildren, not workers (hub match is weak)."
        }
    ]
}

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