The Significance of Primary Tumors in the NTP Study of Chronic Rat Exposure to Cell Phone Radiation]

2019 · Harm · Low evidence

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HarmLow evidencePaper 1660

Study snapshot

Publicationmanual · 2019

Study typereview

Reported directionHarm

Evidence ratingLow

Abstract

The Significance of Primary Tumors in the NTP Study of Chronic Rat Exposure to Cell Phone Radiation] Lin JC. The Significance of Primary Tumors in the NTP Study of Chronic Rat Exposure to Cell Phone Radiation [Health Matters]. IEEE Microwave Magazine. 20(11):18-21. Nov 2019. DOI:10.1109/MMM.2019.2935361 Abstract Most media accounts of the U.S. National Toxicology Program's (NTP's) final report have understandably focused on the statistically significant finding of "clear evidence" that both GSM and code-division multiple access (CDMA)-modulated 900-MHz wireless RF radiation led to the development of malignant schwannoma, a rare form of tumor, in the hearts of male rats. In addition to this, unusual patterns of cardiomyopathy, i.e., damage to heart tissue, were observed in both RF-exposed male and female Sprague-Dawley rats compared with concurrent control animals, although the findings for female rats were deemed as providing only uncertain or "equivocal" evidence for schwannomas and malignant gliomas, compared to concurrent controls. ieeexplore.ieee.org Excerpts "A Closer Look at the NTP Findings "In all fairness, the primary cancer or overall cancer rates detected in any organ or tissue inside the animal body do not appear to have been purposefully overlooked or unnoticed. Indeed, the results for total primary cancer or tumor occurrences in NTP animal studies can be found in the appendices of its final reports [1]. However, although the data may not have been purposefully disregarded or ignored, the NTP excluded them from its publicized report summaries. An independent analysis of the data showed that rats exposed to GSM and CDMA RF radiation had significantly higher overall or total primary tumor rates than did the concurrent control rats [4]. In particular, the highest overall cancer (or malignant tumors) rates were found in male rats exposed to whole- body SARs of 3 W/kg from 900-MHz cell phone RF radiation (42 and 46% for GSM and CDMA, respectively), and the lowest rate was found in the concurrent control group (27%). Thus, the RF-exposed groups had significantly higher overall or total primary cancer rates than did the concurrent control rats. Moreover, the highest overall tumor rates (either a benign or malignant tumor in any organ or tissue) were observed in male rats exposed to SARs of 3-W/kg (87 and 84% for GSM and CDMA, respectively) cell phone RF radiation. As stated previously, the lowest rate was seen in the concurrent control group (63%). The RF-exposed groups had significantly higher overall tumor rates than did the concurrent control rats. Male rats in the lowest RF-exposed groups (whole-body SARs of 1.5 W/kg) had significantly higher rates of benign primary tumors (76 and 73% for GSM and CDMA, respectively) than did concurrent or sham control groups (54%)." "IARC Assessment The International Agency for Research on Cancer (IARC) assessed the then available scientific literature and concluded that the epidemiological studies on humans that had reported increased risks for malignant gliomas and acoustic neuromas among heavy or long-term users of cell phones were sufficiently strong to support a classification of 2B, i.e., possibly carcinogenic to humans [9]. With its classification of RF radiation as a 2B carcinogen, the IARC suggested that it also believed the available scientific evidence was incomplete and limited, especially with regard to results from animal experiments. "The time is right for the IARC to upgrade its previous epidemiology-based classification of RF exposure to higher levels in terms of the carcinogenicity of RF radiation for humans. Recently, two relatively well- conducted RF and microwave exposure studies employing the Sprague-Dawley strain of rats-without, however, using any cancer-promoting agents (or cocarcinogens)-showed consistent results in significantly increased total primary cancer or overall tumor rates in animals exposed to RF radiation." It is important to note that the recent NTP and Ramazzini animal RF exposure studies presented similar findings in heart schwannomas and brain gliomas. The increased schwannomas and abnormal heart tissue development/damage to heart tissue are significant findings in RF-exposed animal research studies. In addition to this, the incidence of benign pheochromocytomas of the adrenal medulla was found to be higher in the exposed group than in the sham controls for the 2,450-MHz circular waveguide experiment [6]. Interestingly, in the recent NTP study, there was "some evidence" of carcinogenicity in the adrenal gland. The number of pheochromocytomas was significantly higher (p <0.05) in male rats at 1.5 and 3 W/kg, compared with the concurrent controls. Moreover, the increase in malignant tumor-like hyperplasia in the adrenal gland of female rats was significantly higher at 6 W/kg, relative to the concurrent controls (p <0.05)." "Postscripts ... It is important to note that the recent NTP and Ramazzini animal RF exposure studies presented similar findings in heart schwannomas and brain gliomas. The increased schwannomas and abnormal heart tissue development/damage to heart tissue are significant findings in RF-exposed animal research studies.... A particular perspective to keep in mind is that, with the induction of cancer by a carcinogen, an agent is typically considered carcinogenic if it induces a significant response in a specific tissue." [4] J. Moskowitz, "National toxicology program publishes final cell phone radiation study reports," Electromagn. Radiation Safety, Nov. 2018. [Online]. Available: saferemr.com

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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 typereview

Effect directionharm

PopulationSprague-Dawley rats (male and female)

Sample sizeNot supplied

ExposureRF · 900 MHz · chronic

Evidence strengthLowConfidence: 66% · Peer reviewed: yes

Main findings

The article summarizes NTP final report findings that GSM- and CDMA-modulated 900-MHz RF exposure showed "clear evidence" for malignant schwannoma in the hearts of male rats, and reports unusual patterns of cardiomyopathy in RF-exposed male and female rats. It also describes an independent analysis indicating significantly higher overall/total primary tumor and overall tumor rates in RF-exposed male rats versus concurrent controls, with higher rates reported at whole-body SARs including 1.5 and 3 W/kg; it further notes increased adrenal pheochromocytomas and adrenal hyperplasia findings at certain SAR levels compared with controls.

Outcomes measured

malignant schwannoma (heart)
malignant glioma (brain)
cardiomyopathy/heart tissue damage
total primary cancer (overall malignant tumors)
overall tumor rates (benign or malignant)
benign primary tumors
pheochromocytoma (adrenal medulla)
adrenal gland hyperplasia (malignant tumor-like)

Limitations

This is a commentary/review of NTP (and other) studies rather than a primary experimental report.
Sample size and detailed methods are not provided in the abstract/excerpts.
Some findings are described as "equivocal" or "some evidence" (e.g., for certain tumors/sexes), indicating uncertainty for parts of the evidence.

View raw extracted JSON

{
  "study_type": "review",
  "exposure": {
    "band": "RF",
    "source": "mobile phone",
    "frequency_mhz": 900,
    "sar_wkg": null,
    "duration": "chronic"
  },
  "population": "Sprague-Dawley rats (male and female)",
  "sample_size": null,
  "outcomes": [
    "malignant schwannoma (heart)",
    "malignant glioma (brain)",
    "cardiomyopathy/heart tissue damage",
    "total primary cancer (overall malignant tumors)",
    "overall tumor rates (benign or malignant)",
    "benign primary tumors",
    "pheochromocytoma (adrenal medulla)",
    "adrenal gland hyperplasia (malignant tumor-like)"
  ],
  "main_findings": "The article summarizes NTP final report findings that GSM- and CDMA-modulated 900-MHz RF exposure showed \"clear evidence\" for malignant schwannoma in the hearts of male rats, and reports unusual patterns of cardiomyopathy in RF-exposed male and female rats. It also describes an independent analysis indicating significantly higher overall/total primary tumor and overall tumor rates in RF-exposed male rats versus concurrent controls, with higher rates reported at whole-body SARs including 1.5 and 3 W/kg; it further notes increased adrenal pheochromocytomas and adrenal hyperplasia findings at certain SAR levels compared with controls.",
  "effect_direction": "harm",
  "limitations": [
    "This is a commentary/review of NTP (and other) studies rather than a primary experimental report.",
    "Sample size and detailed methods are not provided in the abstract/excerpts.",
    "Some findings are described as \"equivocal\" or \"some evidence\" (e.g., for certain tumors/sexes), indicating uncertainty for parts of the evidence."
  ],
  "evidence_strength": "low",
  "confidence": 0.66,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "National Toxicology Program",
    "NTP",
    "cell phone radiation",
    "RF radiation",
    "GSM",
    "CDMA",
    "900 MHz",
    "Sprague-Dawley rats",
    "malignant schwannoma",
    "glioma",
    "cardiomyopathy",
    "tumor incidence",
    "SAR",
    "adrenal pheochromocytoma",
    "IARC"
  ],
  "suggested_hubs": [
    {
      "slug": "who-icnirp",
      "weight": 0.32,
      "reason": "Discusses IARC carcinogenicity classification and calls for reassessment/upgrade based on animal evidence."
    }
  ]
}

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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: 10.1109/mmm.2019.2935361
PubMed: Not supplied

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