Impact of large wildfires on PM10 levels and human mortality in Portugal

Impac o la ge wild i es on PM10 le els and human mo ali y in Po ugal Pa icia Ta ín-Ca asco1, So ia Augus o2,3, Lau a Palacios-Peña1,4, Nuno Ra ola5, and Ped o Jiménez-Gue e o1,6 1Physics o he Ea h, Regional Campus o In e na ional Excellence (CEIR) “Campus Ma e Nos um", Uni e si y o Mu cia, Spain. 2EPIUni - Ins i u o de Saúde Pública, Uni e sidade do Po o, Po o, Po ugal 3Cen e o Ecology, E olu ion and En i onmen al Changes, Faculdade de Ciencias, Uni e sidade de Lisboa (CE3C-FC-ULisboa), Lisboa, Po ugal. 4Dep . o Me eo ology, Me eo ed, Almend icos, Spain. 54. LEPABE-Labo a o y o P ocess Enginee ing, En i onmen , Bio echnology and Ene gy, Facul y o Enginee ing, Uni e si y o Po o, Rua D . Robe o F ias, 4200-465 Po o, Po ugal. 6Biomedical Resea ch Ins i u e o Mu cia (IMIB-A ixaca), Spain. Co espondence: Ped o Jiménez-Gue e o ([email p o ec ed]) Abs ac . Uncon olled wild i es ha e a subs an ial impac on he en i onmen , he economy and local popula ions. Acco ding o he Eu opean Fo es Fi e In o ma ion Sys em (EFFIS), be ween he yea s 2000 and 2013 wild i es bu n abou 170,000-740,000 ha o land annually on he sou h o Eu ope (Po ugal, Spain, I aly, G eece and F ance). Al hough mos sou he n Eu opean coun ies ha e been impac ed by wild i es in he las decades, Po ugal was he mos a ec ed, ha ing he highes pe cen age o 5 bu ned a ea compa ing o i s whole e i o y. Fo his eason, i dese es a close a en ion. Howe e , he e is a lack o knowledge ega ding he impac s o he wild i e- ela ed pollu an s on he mo ali y o he popula ion. All wild i es occu ing du ing he i e seasons (June-July-Augus -Sep embe ) om 2001 and 2016 we e iden i ied and hose wi h a bu ned a ea abo e 1000 ha we e conside ed o he s udy. To assess he spa ial impac o he wild i es, hese we e co ela ed wi h PM10 concen a ions measu ed a nea by backg ound ai quali y moni o ing s a ions, p o ided by he Po uguese En i onmen Agency (APA). Associa ions10 be ween PM10 and all-cause (excluding inju ies, poisoning and ex e nal causes) and cause-speci ic mo ali y (ci cula o y and espi a o y), p o ided by S a is ics Po ugal, we e s udied o he a ec ed popula ions, using Poisson eg ession models. Du ing he s udied pe iod (2001-2016), mo e han 2 million ha o o es we e bu ned in mainland Po ugal and he 48% o wild i es occu ed we e la ge i es. A signi ican co ela ion be ween bu ned a ea and PM10 ha e been ound in some NUTS III ( egions) on Po ugal, as well as a signi ican co ela ion be ween bu ned a ea and mo ali y. No h, cen e and inland o Po ugal a e he15 mos a ec ed a eas. The high empe a u es and long episodes o d ough expec ed on he u u e will inc ease he p obabili ies o ex eme e en s and he e o e, he occu ence o wild i es. 1 h ps://doi.o g/10.5194/nhess-2021-38 P ep in . Discussion s a ed: 12 Feb ua y 2021 c Au ho (s) 2021. CC BY 4.0 License. 1 In oduc ion The exis ence o wild i es cons i u es a conside able impac on he en i onmen and humans li ing in nume ous egions wo ld- wide. Clima e change has la ely been iden i ied as a e y impo an a iable o be conside ed in his ma e and global wa ming20 scena ios a e o ecas ing an inc ease o he numbe and in ensi y o wild i es du ing he nex yea s (Bowman e al., 2017). Global wa ming will p oduce changes in empe a u e and p ecipi a ion pa e ns which will inc ease he p e alence and se e i y o wild i es (Se ele e al., 2015), consequen ly impac ing u u e ai quali y (Schä e al., 2004). In ac , an inc ease on he numbe o d ough s, hea wa es and d y spells is sugges ed by clima e change p ojec ions, which could no only ex end he bu n a ea in ch onically impac ed a eas, bu also a ec new ones (Gille e al., 2004), as was he case o Sweden in he summe 25 o 2018 (Lidskog e al., 2019). One o he a eas o he wo ld mos us iga ed by wild i es is he Medi e anean basin (Po ugal being he mos impac ed coun y), which needs o be s udied ca e ully o add ess he conce ns o local popula ions. Al hough he e has been a sligh dec easing end in he bu n a ea in his egion since 2000 a e an inc easing pe iod in he p e ious 20 yea s (Eu opean En i onmen , Agency, h ps://www.eea.eu opa.eu/da a-and-maps/indica o s/ o es - i e-dange -3/ assessmen ), ecen ex eme e en s like he 2017 i es in Po ugal and he 2018 i es in G eece which e en esul ed in a se e e30 loss o human li es a e con i ming he wo s p ojec ions. In ac , a ecen s udy by Tu co e al. (2019) showed a ela ionship be ween d ough and he occu ence o wild i es and sugges ed an inc ease o bo h due o u u e clima e change. Bu al eady some yea s be o e, he PESETA (P ojec ion o Economic impac s o clima e change in Sec o s o he EU based on bo om-up Analysis) s udy es ima ed an inc ease o he bu n a ea in sou he n Eu ope in he u u e (Cisca e al., 2014). Uncon olled wild i es emi nume ous pollu an s de i ed om he incomple e combus ion o biomass uel, which cause35 damage o human heal h, pa icula ly he espi a o y sys em (Wo ld Heal h O ganiza ion, 2010). Examples include pa icu- la e ma e (PM), ca bon monoxide, me hane, ni ous oxide, ni ogen oxides, ola ile o ganic compounds (VOCs), and o he seconda y pollu an s (Cascio, 2018) ha a e eleased mainly in o he a mosphe e bu can be anspo ed o many o he en- i onmen al compa men s. Mo eo e , hey can a ec he physicochemical p ope ies o he a mosphe e, as o ins ance he in e ac ion o PM wi h sola adia ion which can p omp a modi ica ion o he empe a u e depending on he cha ac e is-40 ics o he ae osol (T en mann e al., 2005). Consequen ly, some o hese chemicals a e egula ed by he Eu opean Di ec i e 2008/50/EC o 21 May 2008 o he Eu opean Pa liamen and o he Council on Ambien Ai Quali y and Cleane Ai o Eu ope, which es ablishes h eshold alues o a sa e ai quali y. Bu al hough wild i e emissions a e a c ucial pa ame e o he local ai quali y (Kno e al., 2016), whe e in some cases he e a e al eady ch onically-exposed popula ions due o he e- quency and dimension o he e en s, hey a e no con ained by poli ical bo de s and can also a ec a eas a om he igni ion45 poin s due o he a mosphe ic anspo o he pollu an plumes. A numbe o s udies (e.g. Lin e al. (2012); Im e al. (2018); Liang e al. (2018); Augus o e al. (2020), among o he s) epo he in luence o na u al and an h opogenic emissions on ai quali y composi ion ac oss di e en coun ies, especially PM and oposphe ic O3. Fo wild i es i is also impo an o ake in o accoun some ac o s which in luence he plume dispe sion, such as he du a ion and space e olu ion o he i e e en and he me eo ological condi ions associa ed (Laza idis e al., 2008). An inc ease o ca dio ascula and espi a o y mo bidi y and50 mo ali y a e some o he impac hese con aminan s can ha e on humans (Johns on e al., 2012; Ta ín-Ca asco e al., 2019). 2 h ps://doi.o g/10.5194/nhess-2021-38 P ep in . Discussion s a ed: 12 Feb ua y 2021 c Au ho (s) 2021. CC BY 4.0 License. Fo ins ance, he e is a s ong e idence o he ela ionship be ween PM in gene al and mo ali y, especially om ca dio ascula diseases, o bo h long- e m and sho - e m exposu e (Ande son e al., 2012). Al hough some s udies co obo a e he exis ence o a link be ween he exposu e o wild i e- ela ed ai pollu an s and hospi al admissions, isi s o eme gency clinics o e en espi a o y mo bidi y (Liu e al., 2015; Reid e al., 2016), he impac s on human heal h a e di icul o quan i y and he eal55 e ec s s ill poo ly known. Rega ding PM, a ecen s udy ocusing on 10 sou he n Eu opean ci ies e ealed ha ca dio ascula and espi a o y mo ali y associa ed o PM10 (pa icles wi h ae odynamic diame e below 10 µm) was highe on days a ec ed by wild i es’ smoke han in smoke- ee days (Faus ini e al., 2015). The au ho s also ound ha PM10 om o es i es inc eased mo ali y mo e han PM10 om o he sou ces. So, he es ima ion o mo ali y due o exposu e o wild i e-gene a ed pollu an s is key o60 manage heal h esou ces and he necessa y public unds owa ds p e en ion and emedia ion, se ing up app op ia e policies and p o ocols (Rappold e al., 2012). The wo main ac o s o ake in o accoun o he wild i e’s e ec s a e he loca ion and, mos impo an ly, he size o he i e e en (cha ac e ised by he espec i e bu n a ea). When he wild i e occu s close o a la ge conu ba ion, he popula ion exposed is highe . Bu as Anali is e al. (2012) showed in hei s udy, small i es do no seem o ha e an e ec on mo ali y, whe eas65 medium and la ge episodes (wi h bu n a eas >1000 ha) ha e a signi ican impac on human heal h, which inc eases wi h he size o he i e. Aiming o enhance he knowledge on he e ec s o wild i es on human heal h, his s udy desc ibes he pa e n o wild i es in Po ugal o 16 yea s (2001-2016) and assesses he impac o hose e en s on he coun y’s popula ion mo ali y du ing he i e season (June, July, Augus and Sep embe ). In his wo k, he ocus is placed on indi ec e ec s o pollu an s emi ed by wild i es, namely assessing he in luence o wild i e-gene a ed PM10 on he Po uguese popula ion mo ali y. The70 ela ionship be ween he size o he wild i e (cha ac e ised by he espec i e bu ned a ea) and PM10 and his same pollu an and mo ali y has been s udied. The Nomencla u e o Te i o ial Uni s o S a is ics (NUTS) le el 3 (NUTS III) geog aphical di ision has been used o be able o compa e he e ec s o he i es in di e en pa s o he coun y. Finally, mon hly dea hs due o all-cause (excluding inju ies, poisoning and ex e nal causes) and cause-speci ic mo ali y (ca dio ascula and espi a o y) o all ages o each NUTS III has been s udied. These causes ha e been selec ed due o hei well-known connec ion wi h ai 75 pollu ion. 2 Me hodology and da a In his s udy, he e ec s o sho - e m pollu an s exposu e due o wild i es on human mo ali y a e quan i ied. The o es i e pollu an emissions we e es ima ed o he pe iod 2001-2016 du ing he summe mon hs (June-July-Augus -Sep embe ) in Po ugal mainland (23 NUTS III and mo e han 10 million people). Fo his quan i ica ion, wo s eps ha e been ollowed.80 Fi s , an assessmen o he incidence, pa e ns and a ia ions o bu ned a ea on a la ge ime ame and spa ially in eg a ed by NUTS III was done on he le els o ai pollu an s. PM10 and bu ned a ea has been co ela ed h ough linea eg ession, while he mo ali y da a and PM10 was co ela ed wi h Poisson eg ession. Da a was p ocessed and o de ed by NUTS and by mon h and yea . Finally, he co ela ion be ween he pollu an s emi ed by o es i es, he wild i es bu ned a ea and he 3 h ps://doi.o g/10.5194/nhess-2021-38 P ep in . Discussion s a ed: 12 Feb ua y 2021 c Au ho (s) 2021. CC BY 4.0 License. di e en causes o mo ali y du ing he pe iod 2001-2016 o he summe mon hs was s udied. The s udy is ocused in PM85 since i is one o he main pollu an s emi ed by wild i es, which can inc ease PM concen a ions up o 50% and mo e (Laza idis e al., 2008). Mo eo e , he e is a clea ela ion wi h se e al e ec s on human heal h (including mo ali y), in pa icula wi h espi a o y and ci cula o y diseases (Kollanus e al., 2016; Reid e al., 2016; Liang e al., 2018). The e was no enough PM2.5 da a collec ed om he Po uguese ai quali y managemen ne wo k o es ablish a co ela ion (only 20 s a ions measu e PM2.5 in he mainland). Fo all hese easons his s udy is ocused on PM10.90 2.1 Ta ge a ea Wi h 89 015 km2(9.11 Mha) mainland Po ugal accoun s o o e 96% o he coun y’s a ea and hos s o e 10 million inhabi an s in he wes Ibe ian Peninsula (sou hwes e n Eu ope). Wi h he la ges u ban a eas along he wes A lan ic coas , pa icula ly a ound he capi al Lisbon mo e o he sou h and he second la ges ci y (Po o) in he no h (see Figu e 1,le ), he coun y has mos o i s moun ain anges in he no h, eaching 1993 m in Se a da Es ela. Al hough showing a Medi e anean95 clima e, his opog aphic display leads o a ious clima e pa e ns along he coun y, wi h inc easing empe a u e and dec easing ain all om no hwes o sou heas (Mo ei a e al., 2011; Oli ei a e al., 2017). In e ms o land co e , Figu e 1,le shows a p edominance o ag icul u e by 2015 (o e 50% and mainly in he sou h), ollowed by o es s and sh ublands, which comp ise 43% o he e i o y (mainly in he no h and sou hwes ). This allied wi h high empe a u es in he summe mon hs ep esen a po en ial i e haza d, which un o una ely has been o en e i ied almos e e y summe o many yea s.100 Figu e 1. (Le ) Land co e in mainland Po ugal in 2015 (Global Fo es Wa ch, h ps://www.global o es wa ch.o g; (Righ ) Mainland Po ugal NUTS III egions as included in his con ibu ion. 4 h ps://doi.o g/10.5194/nhess-2021-38 P ep in . Discussion s a ed: 12 Feb ua y 2021 c Au ho (s) 2021. CC BY 4.0 License. 2.2 Da ase s 2.2.1 NUTS III bounda y da a The a ge domain was di ided by NUTS (Nomencla u e o Te i o ial Uni s o S a is ics) le el 3 (Figu e 1, igh ) o Po ugal mainland. NUTS is a geocode s anda d o e e encing he subdi isions o coun ies o s a is ical pu poses de eloped by he Eu opean Union, and a e di ided in h ee le els, es ablished by each EU membe coun y. The bounda ies o he NUTS III105 iles om mainland Po ugal (in o al, 23) we e e ie ed om he Eu os a web page (h ps://ec.eu opa.eu/eu os a /web/gisco/ geoda a/ e e ence-da a/adminis a i e-uni s-s a is ical-uni s/nu s) wi h QGIS3 so wa e. The downloaded da a a e o he 14 Ma ch 2019 e sion a a 1:60 million scale. 2.2.2 Wild i es da a The wild i e da a, collec ed in he pe iod om 2001 and 2016, was ob ained om he Po uguese Ins i u e o Na u e Conse a-110 ion and Fo es s (h ps://www.icn .p /). Fo his s udy, o es i es occu ing in he mon hs o June, July, Augus and Sep embe 2001-2016 ( he mon hs wi h highes empe a u es and d ie condi ions when mo e han 65% o i es happened) wi h mo e han 1000 ha o o al bu ned a ea we e selec ed and conside ed la ge i es. In o al, he e we e 331 e en s unde ha ca ego y. This da a was di ided by mon h and yea and he espec i e mon hly and yea ly sums we e conside ed o each NUTS III le el egion. A e, Al o Tâmega, Tâmega e Sousa, Oes e, Médio Tejo and Alen ejo Li o al a e he NUTS III whe e la ge i es du ing115 he s udy pe iod we e no ound. 2.2.3 Pollu ion da a The in o ma ion a ailable on he le els o pollu an s was ob ained om he Po uguese En i onmen Agency ai quali y ne - wo k (h ps://quala .apambien e.p /quala /index.php), es ablished o moni o he concen a ions o pollu an s acco ding o he Eu opean Legisla ion equi emen s (Eu opean Di ec i e 2008/50/EC o 21 May 2008). The ne wo k is i egula ly sca e ed120 h oughou he coun y, wi h a s onge p esence in he mos popula ed a eas. The isola ion o pollu an emissions due o bu n biomass is qui e complica ed as i depends on pa ame e s, such as ege a ion ype, he wea he condi ions on he bu n momen o he con ibu ion o o he sou ces, among o he s. Fo his eason, in his s udy, backg ound s a ions (speci ically u ban, sub- u ban and u al backg ound) we e selec ed, so ha he di ec impac o o he u ban and indus ial sou ces such as oad a ic, building hea ing and manu ac u ing combus ions was a oided. Conside ing all he pollu an s measu ed on he backg ound125 s a ions, PM was he one wi h a po en ially highe link o o es i es. And al hough some s a ions also measu ed PM2.5, he co e age was insu icien o d aw any signi ican co ela ions, so PM10 was chosen in he end. As o he wild i es da a, also he e he ime ange was om 2001 o 2016 and only he mon hs o June o Sep embe we e conside ed, wi h mon hly means used o he co ela ions. Concen a ions o PM10 we e ob ained o mainland Po ugal in all ypes o backg ound s a ions (a o al o 91 which co e 17 NUTS III, as shown in Figu e 2)- Gi en he une en co e age o he130 a ge domain, mos s a ions a e loca ed in he me opoli an a eas o Opo o (14 s a ions) and Lisbon (24 s a ions) and in he 5 h ps://doi.o g/10.5194/nhess-2021-38 P ep in . Discussion s a ed: 12 Feb ua y 2021 c Au ho (s) 2021. CC BY 4.0 License. es o he coas al a eas, whe e he highe popula ion (NUTS III commonly abo e 250,000 inhabi an s, Figu e 2) demands a igh e con ol o he ai quali y, bu whe e, in u n, no a lo o la ge wild i es occu due o he u banized land use. Figu e 2. Popula ion o each NUTS III acco ding o he 2011 Census (h ps://www.ine.p ) and espec i e numbe o moni o ing s a ions o PM10. 2.2.4 Mo ali y da a Mo ali y da a co e ing he pe iod om 2001 o 2016 was ob ained om S a is ics Po ugal (h ps://www.ine.p ). Mon hly135 dea h coun s due o all-cause (In e na ional Classi ica ion o Diseases (ICD-10), codes A00-R99) excluding inju ies, poisoning and ex e nal causes; and cause-speci ic mo ali y: ca dio ascula (codes I00-I99) and espi a o y (J00-J99) we e collec ed o each NUTS III egion o Po ugal, comp ising all-age esiden s. These mo ali y causes we e selec ed since hey ha e been epo ed p e iously in li e a u e as impo an in hei connec ion wi h ai pollu ion (Hoek e al., 2013; Liu e al., 2015; Kollanus e al., 2016; Münzel e al., 2018), in pa icula wi h pa icula e ma e (PM). O he ele an mo ali y causes, such as Ch onic140 Obs uc i e Pulmona y Disease (COPD, codes J40-J45) and as hma (ICD-10, code J47), we e also conside ed, howe e he educed numbe o dea hs due o hese diseases in he s udy pe iod p e en ed he es ablishmen o co ela ions. 6 h ps://doi.o g/10.5194/nhess-2021-38 P ep in . Discussion s a ed: 12 Feb ua y 2021 c Au ho (s) 2021. CC BY 4.0 License. 2.3 S a is ical analysis 2.3.1 Co ela ions be ween PM10 and bu ned a ea Co ela ions be ween PM10 and he o al bu ned a ea pe mon h by NUTS III we e es ima ed using Pea son co ela ions145 coe icien s (Pea son and Gal on, 1895). Pea son co ela ion is used o co ela e wo con inuous a iables ha ing a no mal dis ibu ion, while Poisson coe icien s a e used o co ela e a coun a iable wi h a con inuous a iable. These me hodologies a e widely used in s udies co e ing he opic o heal h impac s o ai pollu ion (e.g. Islam and Chowdhu y (2017); Palla és e al. (2019); Rahman e al. (2019); Ro i a e al. (2020); among many o he s). Resul s we e conside ed s a is ically signi ican i he p- alue was p<0.05. Co ela ions we e pe o med using he de ended da a se ies o bu ned a ea and PM10 in o de o emo e150 he s ong seasonal cycle o hese a iables and a oid spu ious co ela ions. The de ending me hod ollows Ta ín-Ca asco e al. (2019), using he i s - ime di e ence ime se ies. 2.3.2 Associa ions be ween bu n a ea, PM10 and mo ali y The associa ions o mon hly a e age PM10 le els, and he size o he wild i es (bu n a ea >1000 ha and bu n a ea <1000 ha) wi h mean mon hly mo ali ies (all-cause, espi a o y and ca dio ascula causes) we e s udied o he mon hs June, July, Augus 155 and Sep embe o he pe iod be ween 2001 and 2016. The e ec es ima es we e ob ained o each NUTS III egion using Pea son eg ession models. The esul s we e exp essed as he Rela i e Risk (RR) o all-cause, ca dio ascula and espi a o y mo ali ies wi h a 95% con idence in e al (95% CI). All eg ession models we e pe o med using IBM SPSS S a is ics 25.0 so wa e. 3 Resul s and discussion160 The esul s ob ained in he s udy a e p esen ed as ollows. Fi s , he desc ip ion o he si ua ion in Po ugal in e ms o geo- g aphical dis ibu ion o he bu ned a ea is p esen ed. Then, a summa y o he PM10 concen a ions du ing he summe mon hs o he yea s 2001-2016 is p esen ed. Finally, he co ela ions be ween bu ned a ea and PM10 and he po en ial associa ions o wild i e-de i ed PM10 and all-cause mo ali y is p esen ed in his sec ion. 3.1 Spa io- empo al pa e ns o wild i es165 3.1.1 Bu ned a ea F om 2001 o 2016 pe iod mo e han 2 million ha o o es we e bu ned in mainland Po ugal. A ound 48% due o la ge i es (>1000 ha). Du ing his pe iod, he wild i es occu ed on di e en a eas in Po ugal, as shown in Figu e 3. The no h, cen e and inland o Po ugal a e he a eas wi h he highes numbe o wild i es and he highes bu ned a ea, being Bei as e Se a da Es ela and Bei a Baixa. Also Lezí ia do Tejo (in Alen ajo) and Alga e (in he sou h) (Figu e 1) can170 be ound among he mos a ec ed a eas (in numbe o wild i es and bu ned a ea). As seen in Figu e 3, he no h and cen e o 7 h ps://doi.o g/10.5194/nhess-2021-38 P ep in . Discussion s a ed: 12 Feb ua y 2021 c Au ho (s) 2021. CC BY 4.0 License. Figu e 3. Bu ned a ea and numbe o i es (>1000 ha) pe NUTS III om June o Sep embe in he pe iod 2001-2016. Po ugal is whe e he mos ex ensi e o es s in he coun y (Nunes e al., 2019), pa icula ly abundan in pine and eucalyp us ees, wo species ha ha e been associa ed wi h ex eme wild i e e en s (Maia e al., 2014). Addi ionally, dense Medi e anean o es s o e ha d- o- each moun ains can also be ound in hese a eas, which combined enhance he di icul y o he i e igh ing e o s. The Alga e, which despi e being loca ed in he sou h coas , also has some moun ains wi h o es s, su ounded by a175 conside ably d y and a id e ain, especially in he summe (Nunes e al., 2019). Bei a Baixa is he egion which p esen ed he mos bu ned a ea du ing he pe iod 2001-2016, wi h almos 124,000 ha in o al. Bu Bei a e Se a da Es ela is he a ea whe e he highes numbe o wild i es was ound, 47 in o al. On he o he hand, Lezí ia do Tejo is he NUTS III egion mos a ec ed by wild i es, conside ing he numbe o la ge i es and bu ned a ea oge he . Oes e and A ea Me opoli ana de Lisboa a e he a eas wi h a smalle numbe o la ge i es, only one du ing he a ge ime ame (since hese a e mainly non- o es ed a eas).180 Table 1 p esen s an o e iew o he bu ned a ea and occu ences o la ge i es by NUTS III a eas in mainland Po ugal. On he o he hand, Table 2 shows he yea ly a iabili y du ing he s udied pe iod o he numbe o he occu ences and bu ned a ea. In 2008 no wild i es o e 1,000 ha o bu ned a ea occu ed, whe eas 2003 accoun ed o 81 o occu ences o la ge i es, which we e esponsible o 80% o he o al bu ned a ea in ha yea . The da a in Table 2 sugges s ha i is no possible o pe cei e a yea ly pa e n o wild i es in Po ugal ega ding he occu ences, bu ned a ea o he con ibu ion o la ge185 i es o he bu ned a ea, bu o he s udies ha e shown a ela ionship wi h high empe a u es and d ough pe iods (Tu co e al., 2019). 8 h ps://doi.o g/10.5194/nhess-2021-38 P ep in . Discussion s a ed: 12 Feb ua y 2021 c Au ho (s) 2021. CC BY 4.0 License. Table 1. To al bu ned a ea and occu ences o la ge i es by NUTS III a eas in mainland Po ugal in he pe iod 2001-2016 in he mon hs o June, July, Augus and Sep embe ( o al o 64 a ge summe mon hs). NUTS Mon hs wi h la ge i es (N) Numbe o la ge i es (N) To al bu ned a ea (ha) No h Al o Minho 7 14 53918 Cá ado 3 4 7731 A e 4 4 5410 Al o Tâmega 10 21 48415 Te as de T ás-os-Mon es 7 10 28050 A. M. Po o 5 8 40840 Tâmega e Sousa 4 4 5706 Dou o 14 27 48907 Cen e A ei o 3 6 17481 Viseu Dão-La ões 11 31 60744 Coimb a 8 16 45673 Bei as e Se a da Es ela 17 49 115503 Lei ia 6 13 28347 Médio Tejo 11 31 96947 Bei a Baixa 7 14 59032 Oes e 1 1 1700 A.M.Lisboa 1 1 2756 Alen ejo Leizí ia do Tejo 2 3 24404 Al o Alen ejo 4 12 70657 Alen ejo Cen al 3 6 1970 Alen ejo Li o al 3 5 16176 Baixo Alen ejo 2 2 9240 Alga e 9 19 107273 9 h ps://doi.o g/10.5194/nhess-2021-38 P ep in . Discussion s a ed: 12 Feb ua y 2021 c Au ho (s) 2021. CC BY 4.0 License. cen e and inland o Po ugal. Wild i es do no ollow a pa e n in numbe o he occu ences o size du ing he yea s s udied. These e idences we e ound despi e he di icul ies ha he une en sca e ing o he ai moni o ing s a ions analysing PM10 in Po ugal posed, since he a eas whe e wild i es a e usually mo e equen (inland) a e a om he u ban cen es (mainly275 along he coas ), and hus, no abundan in ai quali y da a a ailabili y due o he sho age (o e en lack in some NUTS III) o moni o ing s a ions. These egions also ha e an aged popula ion, poo e economy and less heal h ca e esou ces, which can lead o an inc ease in he mo ali y a es in gene al. The socio-economic s a us o he popula ion a ec ed and he heal h ca e acili ies and measu es exis ing in he communi ies ha e o be aken in o accoun (Oli ei a e al., 2017), adding o he coun less pa ame e s ha may a ec hese es ima ions which con ibu e o conside able gaps iden i ied in his ype o s udies (Black280 e al., 2017). Du ing he summe mon hs occu almos 30% o he dea hs o all diseases and ca dio ascula while o espi a o y diseases mo ali y is a ound a 26%, so we can conclude ha cold empe a u es a e in mo e esponsible o all cause dea hs han wa m ones. These episodes occu ed du ing he summe mon hs (June-July-Augus -Sep embe ), when high empe a u es and long285 episodes o d ough inc ease he p obabili ies o unde go one o hese ex eme e en s. On a u u e uled by clima e changes, he high empe a u es and long pe iods o d ough ha usually uel big i es a e expec ed o inc ease, hus leading he way o mo e ex eme and in ense e en s o occu , e en ou side he ypically a ec ed egions. Thus, mo e popula ion will be exposed mo e equen ly o high pollu an le els, a ec ing hei gene al heal h, and inc easing ch onic diseases and mo ali y. Hence, es ic i e policies and p o ocols o imp o e he e ec i eness o p e en i e and mi iga ion ac ions mus be en o ced o ace his290 en i onmen al and socie al issue. Da a a ailabili y. Da a is publicly a ailable h ough he websi es men ioned in he ex : –EFFIS (Eu opean Fo es Fi e In o ma ion Sys em). Da a and Se ices, 2019. A ailable a h ps://e is.j c.ec.eu opa.eu/applica ions/ da a-and-se ices/ (las accessed 11/10/2019). –ICNF (Ins i u o da Conse ação da Na u eza e das Flo es as), 2019. A ailable a h ps://www.icn .p /(las accessed: 01/09/2019).295 –INE (Ins i u o Nacional de Es a ís ica). S a is ics Po ugal - Web Po al, 2019. A ailable a : h ps://www.ine.p /xpo al/xmain?xpid= INE&xpgid=ine_indicado es&con ec o=pi&indOco Cod=0008273&selTab= ab0 (las accessed 16/10/2019). –GWF (Global Fo es Wa ch), 2020. A ailable a h ps://www.global o es wa ch.o g/map/?g w i es= ue (las accessed, 10/10/2020). –PORDATA (Base de Dados Po ugal Con empo âneo). População esiden e: o al e po g andes g upos e á ios (in Po uguese), 2019. A ailable a h ps://www.po da a.p (las accessed 31/03/2020).300 All he compiled da a is a ailable upon con ac ing he co esponding au ho ([email p o ec ed]) Au ho con ibu ions. PT-C w o e he manusc ip , wi h con ibu ions om SA and NR. The manusc ip was inally e ised by PJ-G. P-TC and SA designed he expe imen s and led he s a is ical analysis, wi h he suppo o LP-P, NR and PJ-G. 16 h ps://doi.o g/10.5194/nhess-2021-38 P ep in . Discussion s a ed: 12 Feb ua y 2021 c Au ho (s) 2021. CC BY 4.0 License. Compe ing in e es s. The au ho s decla e no con lic o in e es . Acknowledgemen s. The au ho s a e hank ul o he G-MAR esea ch g oup a he Uni e si y o Mu cia o he ui ul scien i ic discussions.305 Financial suppo . This wo k was inancially suppo ed by he Eu opean Regional De elopmen Fund-Fondo Eu opeo de Desa ollo Re- gional (ERDF-FEDER), Spanish Minis y o Economy and Compe i i eness/Agencia Es a al de In es igación g an numbe CGL2017- 87921-R (ACEX p ojec ) and P ojec UIDB/00511/2020 o LEPABE (Po uguese na ional unds h ough FCT/MCTES PIDDAC); SA was suppo ed by he Po uguese Founda ion o Science and Technology (g an numbe SFRH/BPD/109382/2015). 17 h ps://doi.o g/10.5194/nhess-2021-38 P ep in . Discussion s a ed: 12 Feb ua y 2021 c Au ho (s) 2021. CC BY 4.0 License. Re e ences310 Anali is, A., Geo giadis, I., and Ka souyanni, K.: Fo es i es a e associa ed wi h ele a ed mo ali y in a dense u ban se ing, Occupa ional and En i onmen al Medicine, 69, 158–162, h ps://doi.o g/10.1136/oem.2010.064238, 2012. Ande son, J. O., Thundiyil, J. 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