A moment in time: emergency nurses and the Canterbury earthquakes.

AIM: To outline the impact of the Canterbury, New Zealand (NZ) earthquakes on Christchurch Hospital, and the experiences of emergency nurses during this time. BACKGROUND: NZ has experienced earthquakes and aftershocks centred in the Canterbury region of the South Island. The location of these, around and within the major city of Christchurch, was unexpected and associated with previously unknown fault lines. While the highest magnitude quake occurred in September 2010, registering 7.1 on the Richter scale, it was the magnitude 6.3 event on 22 February 2011 which was associated with the greatest injury burden and loss of life. Staff working in the only emergency department in the city were faced with an external emergency while also being directly affected as part of the disaster. SOURCES OF EVIDENCE: This paper developed following interviews with nurses who worked during this period, and draws on literature related to healthcare responses to earthquakes and natural disasters. The establishment of an injury database allowed for an accurate picture to emerge of the injury burden, and each of the authors was present and worked in a clinical capacity during the earthquake. DISCUSSION: Nurses played a significant role in the response to the earthquakes and its aftermath. However, little is known regarding the impact of this, either in personal or professional terms. This paper presents an overview of the earthquakes and experiences of nurses working during this time, identifying a range of issues that will benefit from further exploration and research. It seeks to provide a sense of the experiences and the potential meanings that were derived from being part of this 'moment in time'. CONCLUSION: Examples of innovations in practice emerged during the earthquake response and a number of recommendations for nursing practice are identified.

Home radon levels and seasonal correction factors for the Isle of Man.

Ionizing radiation dose levels due to home radon can rise to levels that would be illegal for workers in the nuclear industry. It is well known that radon levels within homes and from home to home, and also from month to month, vary considerably. To define an Isle of Man radon seasonal correction factor, readings were taken in eight homes over a 12 month period. An average island indoor exposure of 48 Bq m(-3) (range 4-518 Bq m(-3)) was determined from 285 homes selected from a cohort of 1300 families participating in the European Longitudinal Study of Pregnancy and Childhood (ELSPAC) in the Isle of Man. This compares with a UK home average of 20 Bq m(-3) and a European Union average (excluding UK) of 68 Bq m(-3). Ten homes of those measured were found to have radon levels above the National Radiological Protection Board 200 Bq m(-3) action level. There are 29,377 homes on the Isle of Man, suggesting that there could be some 900 or more homes above the action level. No statistical difference was found between the NRPB and Isle of Man seasonal correction factors.

The contribution of local distribution substations and associated area distribution system to personal exposure to power frequency magnetic fields.

A number of epidemiological studies has shown a significant correlation between wire coding, magnetic fields and childhood cancer, although a more recent study has not [McBride et al. (1999) Am. J. Epidemiol. 149 (9), 831-842]. In the UK there is currently no equivalent to wire-codes and there is some uncertainty about the extent to which the UK medium-voltage electricity distribution systems contribute to personal exposure and how this compares with US overhead supply systems. Studies on four different area types were carried out to measure magnetic field intensities from typical electricity supply utility substations and cabling in the vicinity of domestic housing. Typically at distances of two metres from the substations mean magnetic field intensities were 20 nano teslas (nT) or less, increasing to 0.98 microT or less at the closest public access point. The mean magnetic field exposure level sampled around the four main test areas varied between 0.012 and 0.27 microT increasing to 0.30-0.80 microT at road junctions.

Magnetic fields from domestic appliances in the UK.

In a survey of 50 UK homes the 50 Hz fundamental and harmonic magnetic fields generated by 806 domestic appliances found in the homes, and used regularly by mothers, were measured. Measurements were made in the direction of most likely access, and from the surface of the appliances. Mothers completed a questionnaire on the use of appliances and were monitored for 24 h so that acquired exposure could be compared with the measured ambient fields in the home. Appliances were measured at standard distances and an algorithm was used to calculate fields at 100 and 50 cm to remove room background contributions. A few appliances generated fields in excess of 0.2 microT at 1 m: microwave cookers 0.37 +/- 0.14 microT; washing machines 0.27 +/- 0.14 microT; dishwashers 0.23 +/- 0.13 microT; some electric showers 0.11 +/- 0.25 microT and can openers 0.20 +/- 0.21 microT. Of continuously operating devices, only central heating pumps (0.51 +/- 0.47 microT), central heating boilers (0.27 +/- 0.26 microT) and fish-tank air pumps (0.32 +/- 0.09 microT) produced significant fields at 0.5 m. There were no obvious ways to group different types of appliances as high- or low-strength sources. Mothers spent on average about 4.5 h per day in the kitchen, where the strongest sources of magnetic field were located.

Domestic magnetic field exposures in Avon.

To define a protocol for surrogate measurement of magnetic field exposure by questionnaire, a series of spot and 24-hour measurements was made at 50 houses in Avon, UK. Measurements were made with Emdex II equipment in the centres of rooms with the house power encountered at the start of the visit, and then with all power to the house isolated at the main switch. The mean spot magnetic field averaged over the 50 homes for each room varied between 0.011 and 0.023 microT with an overall mean (0.017 +/- 0.003) microT with the power 'on', and between 0.008 and 0.015 microT, giving an overall mean (0.012 +/- 0.002) microT with power 'off'. Measurements over 24 h in the three main occupancy rooms showed a distinct diurnal variation in the overall mean magnetic field of the 50 homes by a factor of three, giving a 24-hour mean of (0.044 +/- 0.06) microT; at the same time mean recorded personal exposure for the occupants monitored was (0.067 +/- 0.08) microT. These values appear low compared with, for example, USA domestic levels of magnetic field exposure demonstrated in several studies, but also show a wide variation in individual values, which could not be predicted from spot measurements.