['ren', 'Euan', 'nn', 'TABLE', '¢.', 'Comparisen', 'ef', 'lndoor', 'sad', 'Outlooe', 'VOC', 'Concentrations', '(uy', 'a)', 'fer', '12', 'Homes’', 'indoor', '(x', '=', 'G4)', 'outdoor', '{a', '=', '54}', '.', 'wat', 'was', '50.', 'median', 'mex', 'oecn', '|S', 'median', 'min', 'ma', 'YO"', 'retio', '«=', 'Wiicozmm', 'test?', '1.3-dutadiene', '11', '1.9', '08', 'nde', '10.8', 'Og', 'az', '°', '03', 'nae', '(09', '66', '+', 'benzene', '138°', '(138', '«(9.2', '26', '637', '%73', '60', '56.1', 'a7', '73.8', 'a4', 're', 'toluene', '3s', '217', 'wa', '88', '99.3', 'Wr', '127', '112', '22', '«75.7', '4.0', '+', 'ethylbenzene', '23', '130', '(20', '0.6', '65', '16', '14', 'nZ', '02', '84', '23', 'aa', 'p-xylene', '19', 'Wt', '18', 'o5', 'Ba', '14', '13', '3.1', '02', '73', '22', '+e', 'rexylene', '5.4', '320', '«48', '13', '16.1', '38', '3700', '«30', '05', '225', '23', '+', 'oxylene', '19', '13', '1.6', 'oa', '63', '6', '1.3', '1.2', '02', '7.5', '21', '+e', '1.3,5-TM8', '95', 'GS', '03', 'ade', '2300«(-OF:', '602', '2', 'nde', '1.2', '21', '+.', 'styrene', 'o8', '0.7', '05', 'ng?', '34', '0.4', 'oF', 'o2', 'nde', '4.4', '43', '+e', '1,2,TMB', '17', '19', '1.0', 'o3', '3.6', 'Ut', 'oa', 'OB', 'nde', '=', '5.2', '21', 'ae', '-ethenylpyridine', 'OE', '1', 'nde', 'nd*', '59', '-', '-', 'rd?', 'naeonds', '-', '+', 'naphthalene', 'og', '10', '«0.5', '0.2', '6.0', '0.3', 'a2', '02', 'nee', '09', '42', '+e', 'pyridine', 'O4', '12', 'nd', 'nde', '6.8', '-', '.', 'nae', 'nd', 'ad', '.', '+', '4', 'The', 'mean', 'of', 'VO', 'ratios.', 'Wilcoxon', 'test', '(Wileoxcn', 'rank', 'sum', 'W', 'test).', '«(+', 'significantly', 'dilferert', 'at', 'the', '0.05', 'level.', '*', 'VI4S-TMB', '11.35-', 'trimethyibenzenel,', 'olPT', 'ip-isopropyhaluene),', 't.2,.4-TM8', '$1,2,4-Icimethylbenzenel,', '14-DC8', '(1,4-dichton', 'benzane).', '*', 'nd', '=', 'nat', 'detocted.', ' ', 'autcmabiles', 'during', 'sampling,', 'It', 'is', 'highly', 'probable', 'that', 'concentrations', 'in', 'newer', 'cars', 'in', 'the', 'absence', 'of', 'smoking', 'would', 'be', 'lower', 'than', 'the', 'mean', 'values', 'recorded', 'in', 'our', 'study,', 'and', 'it', 'ix', 'stressed', 'that', 'our', 'limited', 'dataset', 'should', 'not', 'be', 'taken', 'as', 'representative', 'of', 'VOC', 'concentrations', 'in', 'vehicles', 'in', 'general.', 'since', 'the', 'mean', 'age', 'of', 'automobiles', 'monitored', 'in', 'this', 'study', '(which', 'were', 'all', 'owned', 'by', 'graduate', 'students)', 'is', 'likely', 'to', 'be', 'appreciably', 'greater', 'than', 'that', 'of', 'the', 'U.K', 'deer', 'overall.', 'High', 'VOC', 'concentrations', 'were', 'also', 'found', 'in', 'pubs.', 'in', 'this', 'study,', 'six', 'pubs', 'were', 'selected,', 'with', 'smoking', 'occurring', 'during', 'every', 'sampling', 'event.', 'Mean', 'cancenqations', 'of', '1,3-', 'butadiene', 'and', 'styrene', 'in', 'pubs', 'were—with', 'the', 'exception', 'af', 'those', 'recorded', 'in', 'cars—the', 'highest', 'recorded', 'at', '3.0', 'pg', 'm~?', 'and', '2.1', '~g', 'm7},', 'respectively.', 'in', 'this', 'study,', 'mean', 'concentrations', 'of', 'some', 'VOCs', 'in', 'automobiles.', 'pubs,', 'and', 'gain', 'stations', 'exceeded', 'or', 'were', 'comparable', 'fo', 'those', 'at', 'heavily', 'trafficked', 'roadside', 'locations,', 'which', 'have', 'long', 'been', 'considered', 'as', 'representadve', 'worst-', 'case', 'scenarios', 'for', 'air', 'pollution.', 'The', 'presence', 'of', 'elevated', 'concentrations', 'in', 'such', 'widely', 'frequented', 'microenviron-', 'ments', 'could', 'therefore', 'have', 'appreciable', 'implications', 'for', 'public', 'health.', 'Indoor', 'Alr', 'Quality', 'in', 'Homes.', 'Indoor-Outdoor', 'Concen-', 'tation', 'Ratios.', 'Mean', 'indooroutdoor', '(1/0)', 'concentration', 'ratios', 'of', 'VOCs', 'in', 'homes', 'are', 'given', 'in', 'Table', '4.', 'Mean', 'concentrations', 'were', 'higher', 'in', 'indoor', 'air', 'rhan', 'in', 'outdoor', 'air', 'for', 'al}', 'VOCs.', 'as', 'previously', 'ceponed', '(20.', '16.', '17).', 'Mean', 'concentrations', 'of', '1,3-butadiene', 'and', 'benzene', 'indoors', 'were', '1.1', 'and', '13.9', '2g', 'm3,', 'with', 'mean', '[/O', 'radios', 'of', '6.6', 'and', '3.4,', 'respectively.', 'Interestingly,', 'aur', 'data', 'show', 'that', 'indoor', 'con-', 'centrations', 'do', 'not', 'always', 'exceed', 'those', 'outdoors,', 'as', 'the', 'maximum', 'concentrations', 'of', 'the', 'xylenes', 'and', 'ethytbenzene', 'recorded', 'outside', 'exceed', 'the', 'maxima', 'recorded', 'indoors.', 'Closer', 'inspection', 'of', 'our', 'data', 'revealed', 'that', 'che', 'madimum', 'outdoor', 'concentrations', 'were', 'recorded', 'outside', 'a', 'home', 'that', 'was', 'located', 'within', '10', 'm', 'ofa', 'busy', 'road.', 'The', 'existence', 'afa', 'possible', 'relationship', 'between', 'VOC', 'concentrations', 'recorded', 'indoors', 'and', 'outdoors', 'was', 'statistically', 'evaluated', 'using', 'the', 'Wilcoxon.', 'rank', 'sum', 'W', 'test,', 'with', 'results', 'shown', 'in', 'Table.', 'This', 'test', '©', 'evaluates', 'whether', 'there', 'are', 'significant', 'differences', 'between', 'two', 'datasets—in', 'this', 'instance', 'indoor', 'and', 'outdoor', 'VOC', 'concentrations.', 'The', 'test', 'is', 'appropriate', 'in', 'this', 'context,', 'as', 'ir', 'ls', 'a', 'nonparametric', 'test', 'designed', 'for', 'the', 'evaluation', 'of', 'datasets', 'such', 'as', 'these', 'that', 'do', 'not', 'display', 'normal', 'distribuven.', 'For', 'all', 'VOCs,', 'indoor', 'and', 'outdoor', 'concentrations', 'were', 'shown', 'to', 'be', 'significandy', 'different', '(p', '<', '0.05).', 'The', 'diurnal', 'variations', 'in', 'concentrations', 'of', '1.3-buladiene.', 'styrene.', 'benzene.', 'and', 'toluene', 'both', 'indoors', 'and', 'outdoors', 'in', 'one', 'smoking', 'home', 'and', 'one', 'nonsmoking', 'home', 'over', 'a', 'period', 'of', '24', 'h', 'are', 'shown', '1000', '6', 'ENVIRONMENTAL', 'SCIENCE', '&', 'TECHNOLOGY', '/', 'VOL', '98,', 'NO.', '6.', '2007', 'in', 'Figures', '1', 'and', '2,', 'respe', 'xtively.', 'In', 'the', 'nonsmoking', 'home.', 'though', 'the', 'parerus', 'of', 'VOC', 'concentrations', 'are', 'very', 'similar', 'Indoors', 'and', 'outdoors,', 'the', 'peak', 'times', 'of', 'these', 'concentrations', 'are', 'not', 'coincident', 'in', 'th', 'two', 'environments.', 'in', 'addition.', 'there', 'is', 'generally', 'a', 'tim2', 'lag,', 'with', 'the', 'outdoor', 'increase', 'pteceding', 'that', 'observed', 'indoors,', 'Furthermore,', 'the', 'rise', 'in', 'indoor', 'concentrations', 'ge:', 'erally', 'starts', 'from', 'a', 'higher', 'baseline', 'than', 'outdoors.', 'In', 'the', 'sm', 'oking', 'home,', 'the', 'diurnal', 'variations', 'of', 'VOC', 'concenmations', 'indoors', 'and', 'outdoors', 'are', 'very', 'different', 'with', 'a', 'particularly', 'marked', 'dichotomy', 'observed', 'during', 'smoking', 'events.', 'The', 'concentration', 'of', 'indoor', 'pollutants', 'is', 'conuolled', 'by', 'several', 'factors:', 'the', 'most', 'prominent', 'being', 'the', 'following.', 'the', 'volume', 'of', 'air', 'containec.', 'in', 'the', 'indoor', 'environment', 'the', 'emissjon/removal', 'rate', '¢f', 'the', 'pollutant', 'in', 'the', 'indoor', 'mi-', 'croenvironment;', 'the', 'bui', 'ding', 'ventilation', 'rate:', 'and', 'ourdoor', 'concentrations', '(/3).', 'In', 'this', 'study.', 'building', 'veritilation', 'rates', 'were', 'not', 'measured', 'buta', '¢', 'considered', 'likely', 'to', 'be', 'low,', 'since', 'all', 'sampling', 'was', 'conduc', '.ed', 'over', 'a', 'period', 'when', 'the', 'average', 'daily', 'maximum:', 'outdeo™', 'air', 'temperature', 'recorded', 'on', 'the', 'University', 'of', 'Birmingham', 'campus', 'was', '8,2', '°C.', 'Therefore.', 'although', 'it', 'is', 'recognized', 'that', 'the', 'situation', 'may', 'differ', 'in', 'surnmer', 'or', 'in', 'locations', 'benefiting', 'from', 'a', 'warmer', 'climate—', 'the', 'presence', 'orabsence', 'tf', 'indvor', 'sources', 'of', 'VOCs', 'is', 'deemed', 'the', 'most', 'important', 'factor', 'controlling', 'the', 'indoor', 'air', 'quality', 'of', 'homes', 'in', 'this', 'comp', 'ivatively', 'small', 'srudy.', 'This', 'survey', 'revealed', 'higher', 'mean', 'inc', 'oor', 'concentrations,', 'no', 'relationship', 'between', 'simultaneousl’', 'measured', 'indoor', 'and', 'outdoor', 'concenuations,', 'and', 'sign', 'ficantly', 'different', 'patterns', 'of', 'diurnal', 'variation', 'in', 'VOC', 'concentrations', 'recorded', 'indoors', 'and', 'outdoors.', 'Thus—in', 'poorls', 'ventilated', 'buildings—indoor', 'emis-', 'sion', 'source', 'suength', 'appears', 'to', 'be', 'a', 'more', 'significant', 'influence', 'on', 'concentradons', 'of', 'VOCs', 'in', 'indoor', 'air', 'than', 'outdoor', 'air', 'concentrati:ns.', 'VOC', 'Concentrations', 'in', 'Smoking', 'Homes', 'Compared', 'with', 'Nonsmoking', 'Homes.', 'The', 'airbome', 'concentrations', 'of', 'VOCs', 'In', 'six', 'smoking', 'homes', 'and', 'six', 'nonsmoking', 'homes', 'are', 'compared', 'In', 'Table', '5.', 'Me', 'an', 'concenwations', 'of', '1.3-butadiene', '“and-benzene', 'in-smoking', 'homes', 'were', '1,7-and', '15.3', 'ag', 'm”?..', 'respectively,', 'i.e.', '3.4', 'tims', 'and', '1.4', 'dmes', 'higher', 'than', 'those', 'in', 'nonsmoking', 'homes.', 'Statistical', 'evaluation', 'using', 'the', 'Wilcoxon', 'rank', 'sum', 'W', 'test', 'revealed', 'significanc', 'differences', 'benween', 'concentrations', 'in', 'smoking', 'and', 'nonsmoking', 'homes', 'for', 'all', 'VOCs', 'except', 'styrene.', '1.4-dichiorobenzene,', 'and', 'naphihalene.', 'Interestit', 'gly,', 'while', 'concentadons', 'of', '13-', 'butadiene', 'and', 'benzene', 'vere', 'significantly', 'higher', 'in', 'smoking', 'homes,', 'those', 'of', 'most', 'cther', 'aromatic', 'VOCs', 'were', 'higher', 'in', 'nonsmoking', 'homes.', 'This', 'is', 'a', 'clear', 'indication', 'of', 'the', 'plethora', '_of', 'additfonal,', 'non-ETS', 'sources', 'of', 'VOCs', 'in', 'domesilc', 'mi-', ' ', 'PM3006713842']