Effect of x-ray exposure (mAs) on peroxide and acid values of honey.

Honey is used in most places as food sweetener and antibacterial agent for wounds. The antibacterial property of honey depends mainly on its peroxide value and acidity. This study investigated the possible effect that may be observed on the peroxide value and acidity if honey is exposed to x-ray at varying tube current values (mAs) in order to infer the possible implications of referring patients undergoing honey therapy for diagnostic x-ray examination. The acid and peroxide values were found to vary with changes in the exposure (mAs) value. It is therefore recommended that patients undergoing honey therapy should be referred for diagnostic x-ray examination with caution while radiotherapy should be avoided.

Use of mobile phones and changes in cognitive function in adolescents.

BACKGROUND: Several studies have investigated the impact of mobile phone exposure on cognitive function in adults. However, children and adolescents are of special interest due to their developing nervous systems. METHODS: Data were derived from the Australian Mobile Radiofrequency Phone Exposed Users' Study (MoRPhEUS) which comprised a baseline examination of year 7 students during 2005/2006 and a 1-year follow-up. Sociodemographic and exposure data were collected with a questionnaire. Cognitive functions were assessed with a computerised test battery and the Stroop Color-Word test. RESULTS: 236 students participated in both examinations. The proportion of mobile phone owners and the number of voice calls and short message services (SMS) per week increased from baseline to follow-up. Participants with more voice calls and SMS at baseline showed less reductions in response times over the 1-year period in various computerised tasks. Furthermore, those with increased voice calls and SMS exposure over the 1-year period showed changes in response time in a simple reaction and a working memory task. No associations were seen between mobile phone exposure and the Stroop test. CONCLUSIONS: We have observed that some changes in cognitive function, particularly in response time rather than accuracy, occurred with a latency period of 1 year and that some changes were associated with increased exposure. However, the increased exposure was mainly applied to those who had fewer voice calls and SMS at baseline, suggesting that these changes over time may relate to statistical regression to the mean, and not be the effect of mobile phone exposure.

Use of hardware modified phones for exposure assessment in health studies in Australia: verification of compliance with standards.

Most epidemiological studies investigating health effects of mobile telephone use have been criticised for poor quality of exposure assessment. Most used questionnaires which have limited precision to assess exposure. Clearly more relevant and direct methods of exposure assessment are needed. We describe the calibration of hardware modified phones (HMPs) for exposure assessment and dosimetry and verified their compliance with Australian and international standards. Specific energy absorption rate (SAR) values at various tilts and rotations and their combinations were obtained for the HMPs using a 'DASY3' SAR measuring system. Calibration involved placing HMPs on human head phantoms and taking measurements at 900 and 1800 MHz bands on right and left sides of the phantom. At 900 MHz the maximum SAR obtained with HMPs at the touch position was 0.9 W/kg and 0.4 W/kg at 30 degrees tilt but at 1800 MHz, SAR at the touch and 30 degrees tilts were 1.1 W/kg and 1.3 W/kg respectively. Whilst tilt and rotation each had an effect on SAR at constant frequency, no interaction was observed with rotation and frequency, however one was observed between tilt and frequency. At 1800 MHz mean SAR at 30 degrees tilt was 0.22 W/kg higher (95% CI 0.15, 0.30) than at 0 degrees, whereas at 900 MHz mean SAR at 30 degrees tilt was 0.60 W/kg lower (95% CI 0.52, 0.67) than at 0 degrees. Our results indicated that tilts influence SAR more than rotations. SAR values obtained at both 900/1800 MHz for the HMPswere well below ICNIRP limits for the general public. The phones were compliant with both international and Australian standards.

Radiation exposure levels within timber industries in Calabar, Nigeria.

The UNSCEAR (2000) observed that there could be some exposure at work which would require regulatory control but is not really considered. This study was, therefore, set up to evaluate the effective dose in timber industries in Calabar, Nigeria to determine if the evaluated dose levels could lead to any radiological health effect in the workers, and also determine if the industries require regulatory control. The gamma ray exposure at four timber industries measured using an exposure meter were converted to effective dose and compared with the public and occupational values. The evaluated effective dose values in the timber industries were below public and occupational exposure limits and may not necessarily result in any radiological health hazard. Therefore, they may not require regulatory control.

Mobile phones and brain tumours: a review of epidemiological research.

There has been a great deal of public concern regarding the possibility that the use of mobile phone-related technologies might result in adverse health effects. Corresponding to this, there has been substantial epidemiological research designed to determine whether the use of mobile phones (MP) has any effect on health, and in particular whether it increases the risk of developing head and neck tumours. Such literature is particularly heterogeneous, which makes it difficult to pool in a meta-analysis. This paper thus reviews the epidemiological literature pertaining to the use of mobile phones and mobile phone-related technologies, and head and neck tumours, in an attempt to consolidate the various reports. Although there have been individual reports of associations between MP-use and tumours, this research is not consistent and on balance does not provide evidence of an association. There are reports of small associations between MP-use ipsilateral to the tumour for greater than 10 years, for both acoustic neuroma and glioma, but the present paper argues that these are especially prone to confounding by recall bias. The reported associations are in need of replication with methods designed to minimise such bias before they can be treated as more than suggestive.

Effect of aqueous leaf extract of Irvingia gabonensis on gastrointestinal tract in rodents.

Effect of the aqueous leaf extract of I. gabonensis on the gastrointestinal tract was investigated on isolated rabbit jejunum, guinea pig ileum, gastrointestinal motility, castor oil-induced diarrhoea in mice and castor oil-induced fluid accumulation in rats. The results showed that the extract exhibited a concentration-dependent relaxation of spontaneous pendular movement of isolated rabbit jejunum and guinea pig ileum, and attenuated both acetylcholine-induced contraction of rabbit jejunum and histamine-induced contraction of guinea pig ileum. The extract (100, 200 and 400 mg/kg) also caused a significant dose-dependent decrease of gastrointestinal motility in mice (40.12, 39.45 and 37.45%), intestinal fluid accumulation in rats (71.43, 81.63 and 83.27%), and remarkably protected mice against castor oil-induced diarrhoea [58.33, 75 and 91.67% (Di Carlo score)] respectively. Preliminary phytochemical screening of the aqueous leaf extract of I. gabonensis revealed the presence of saponins, tannins, phenols and phlobatanins.

Chloroquine reduces blood pressure and forearm vascular resistance and increases forearm blood flow in healthy young adults.

The effects of chloroquine on resting blood pressure, forearm blood flow (FBF), and forearm vascular resistance (FVR) and on the responses to cold stimulation were studied in healthy young adults. Chloroquine sulphate (800 mg) reduced systolic pressure and increased FBF (P < 0.05) but had no effect on resting FVR. Cold immersion increased systolic pressure (from 108.8 +/- 1.7 mmHg to 127.8 +/- 6.9 mmHg; P < 0.05) diastolic pressure (from 73.4 +/- 2.7 to 95.2 +/- 6.2 mmHg; P < 0.01) and FVR (from 5.9 +/- 0.9 to 13.0 +/- 1.9 a.u.; P < 0.001) but reduced FBF (from 14.3 +/- 1.64 to 10.1 +/- 1.29 ml min-1; P < 0.05). Chloroquine reduced the increase in FVR reduced by cold stimulation (P < 0.01), but had little effect on the BF and FBF responses to cold stimulation. The hypotensive effect of chloroquine could be attributed, at least in part, to the observed fall in vascular resistance.