INTERNATIONAL JOURNAL OF CLIMATOLOGY Int. J. Climatol. 33: 2551–2560 (2013) Published online 1 November 2012 in Wiley Online Library (wileyonlinelibrary.com) DOI: 10.1002/joc.3610 Heat-related mortality in Moldova: the summer of 2007 Roman Corobov, a * Scott Sheridan, b Nicolae Opopol c and Kristie Ebi d a Eco-TIRAS International Environmental Association, Chisinau, Moldova b Department of Geography, Kent State University, Kent, OH, USA c Department of Hygiene and Epidemiology, State Medical and Pharmaceutical University, Chisinau, Moldova d Department of Global Ecology, Carnegie Institution for Science, Stanford, CA, USA ABSTRACT: Heat waves of 2007 in Chisinau (Moldova) were used to study the relationship between elevated temperatures and excess mortality caused by these events. As reference information, daily temperature and mortality data for an 8-year reference period (2000–2008 without 2007) were used. Mean (T mean ), maximum (T max ) and minimum (T min ) daily air temperatures, and corresponding apparent temperatures (ATs) in the warm season (April to September) were correlated with excess total mortality in 2007, taken as the difference of daily death counts or their 7-d moving averages with those of the reference period. Observed excess mortality was totalled about 190–200 deaths or 6.5–6.9% of the reference mortality. The average daily excess deaths above the threshold temperatures (TTs), in terms of a used ‘estimator’ (a temperature variable), were in the range of 2.0–4.4% per 1 ◦ C. TTs were identified as the lowest 2 ◦ C class intervals above which the excess mortality rates began a sharp increase from their zero reference value. For T mean , T max and T min they were estimated as ∼25, 31 and 19 ◦ C; TTs for ATs were somewhat lower. The heat waves were defined as a continuous period satisfying three conditions for daily T max : (1) it is above the 99th percentile of its reference distribution (2000–2008) for at least three consecutive days, (2) its average value is equal to at least this percentile for the entire period and (3) all daily values are above 90th percentile for the entire period. On the whole, eight heat events caused 146 excess deaths or about 73–77% of their total number in the warm period of 2007. Temperature–excess mortality relationships become stronger with an increasing time lag; maximal effects were revealed on the second–third days for T mean and T max , and on the first–second days for T min . The total effect of mortality displacement was estimated as about 17–25% of ‘positive’ excess deaths. KEY WORDS heat wave; excess death; threshold temperature; mortality displacement; lag effect Received 21 April 2011; Revised 20 August 2012; Accepted 25 September 2012 1. Introduction Mortality rates are ambient temperature dependent and have long been associated with the effects of both heat and cold. Research by epidemiologists and climatologists has grown rapidly following the European heat waves in 2003 (Sch¨ ar et al., 2004; Carson et al., 2006; Laaidi et al., 2006; Confalonieri et al., 2007; Gosling et al., 2007, 2009a, 2009b; Matthies et al., 2008; Basu, 2009; Jendritzky and de Dear, 2009; Menne and Matthies, 2009; Tob´ ıas et al., 2010). That summer many western European countries experienced dramatic death tolls, and temperatures were considered as ‘a shape of things to come’ (Beniston, 2004). The analysis of isolated extreme events in addition to the mean climate is supported by empirical evidence that impacts of high temperatures are different from those associated with variability in the mean climate: they tend to be greater within a shorter time frame (Hanson et al., 2007). Moreover, such analysis * Correspondence to: R. Corobov, Eco-TIRAS International Envi- ronmental Association, 9/1, Independentii str., apt. 133, MD 2028, Chisinau, Moldova. E-mail: rcorobov@gmail.com. provides an useful insight into the short-term response of populations to these events at the regional level. Although the extremely hot summer of 2003 in West- ern Europe is well-known and well-studied (Parry et al., 2007; Euroheat, 2009; D’Ippoliti et al., 2010), another hot summer, in 2007, concentrated more significantly in southeastern Europe, has not received as much atten- tion. This year was one of the warmest in the history of instrumental observations in Greece (Founda and Gian- nakopoulos, 2009), Romania (Busuioc et al., 2007) and Moldova; in the latter, practically all temperature records were broken in winter, spring and especially in sum- mer, including the all-time record maximum temper- ature of 41.5 ◦ C, reported on 21st July (Bugaeva and Mironova, 2007). Similar to the perception of 2003 in western and central Europe (Beniston, 2004), the year 2007 also appears unusual given Moldova’s historical cli- mate (Corobov et al., 2010). This fact, along with general drying of Moldova’s climate and a nearly complete lack of national biometeorological studies in recent times, has triggered this research. Several basic aspects shaped its content. The first issue for debate is how heat waves should be defined. In the absence of an adequate definition, it is impossible to  2012 Royal Meteorological Society