Available online at www.tshe.org/ea/index.html EnvironmentAsia AvailableEnvironmentAsia online at www.tshe.org/EA 9(1) (2016) 1-8 The international journal published by the Thai Society of Higher Education Institutes on Environment EnvironmentAsia DOI 2 (2009) 50-54

Genotoxicity Assessment of Mercuric Chloride in the Marine Fish Therapon jaruba A Ten-Year Investigation on Ozone and It Precursors at Nagarajan Nagarani, ArumugamKemaman, Kuppusamy Terengganu, Kumaraguru, Malaysia Velmurugan Janaki Devi and Chandrasekaran Archana Devi Marzuki Ismail a, Samsuri Abdullah a, Fong Si Yuen a and Nurul Adyani Ghazali b Center for Marine and Coastal Studies, School of Energy, Environment and Natural Resources, a School of Marine ScienceMadurai and Environment, Kamaraj University, Universiti MalaysiaMadurai-625021, Terengganu, India 21030 Kuala Terengganu, Terengganu, Malaysia b School of Ocean Engineering, Universiti Malaysia Terengganu, 21030 Kuala Terengganu, Abstract Terengganu, Malaysia

The aim of the present study was to standardize and to assess the predictive value of the cytogenetic analysis byAbstract Micronucleus (MN) test in fish erythrocytes as a biomarker for marine environmental contamination. Micronucleus frequency baseline in erythrocytes was evaluated in and genotoxic potential of a common chemical was determined in fish10 experimentally years of continuous exposed monitoring in aquarium data under (2000-2010) controlled conditions. from Air QualityFish (Therapon Division, jaruba Malaysian) were exposed Department for 96 of hrsEnvironment to a single areheavy used metal to investigate(mercuric chloride). the relationships Chromosomal between damage ambient was determinedlevels of ozone as micronuclei (O3), nitric frequency oxide (NO) in fishand erythrocytes.nitrogen dioxide Significant (NO2) asincrease a function in MN of frequency NOx, in Kemaman,was observed Malaysia, in erythrocytes wherewith of fish the exposeddominant to sourcesmercuric of chloride.ozone precursors Concentration are industrialof 0.25 ppm activities induced theand highest road MNtraffic. frequency In addition, (2.95 micronucleated variation of oxidant cells/1000 OX cells (O3 compared and NO2) toconcentration 1 MNcell/1000 with cellsNOx wasin control also examined. animals). The The analyses study revealed established that amicronucleus weak linear relationshiptest, as an indexbetween of cumulativeO3 and NOx, exposure,signifying appearsthat Kemaman to be a area sensitive is not modelNOx sensitive to evaluate but possiblygenotoxic VOC-sensitive compounds inarea. fish The under level controlled of [OX] isconditions. influenced by

NOx-independent and NOx-dependent contributions. The former is due to regional background O3 concentration while the Keywords:latter correlates genotoxicity; to the local mercuric level of chloride;primary pollution. micronucleus The measured concentrations of the pollutants varied as a function of time. The analyses also show that the diurnal cycle of ground level ozone concentration has a mid-day peak while lower concentration occurs at night time.

1.Keywords: Introduction ground level ozone; solar radiation intensity; diurnallaboratory cycle; oxidant; and field Kemaman conditions. In 2006 Soumendra et al., made an attempt to detect genetic biomarkers In India, about 200 tons of mercury and its in two fish species, Labeo bata and Oreochromis 1. Introduction primary and secondary pollutants, as well as ambient compounds are introduced into the environment mossambica, by MN and binucleate (BN) meteorological factors. Owing to the chemical coupling annually as effluents from industries (Saffi, 1981). erythrocytes in the gill and kidney erythrocytes Ozone is a secondary pollutant resulting from of O and NO , the levels of O and NO are inextricably Mercuric chloride has been used in agriculture as a exposed3 to xthermal power3 plant 2discharge at photochemical reaction of variety of natural and linked. The changes in the local level of O and NO will fungicide, in medicine as a topical antiseptic and Titagarh Thermal Power Plant, Kolkata,3 India. 2 anthropogenic precursors; mainly volatile organic lead to an increasing background level. In this study, disinfectant, and in chemistry as an intermediate in The present study was conducted to determine compound (VOC) and oxides of nitrogen (NO ). ten years ambient concentration data of O , NO, NO , the production of other mercury compounds. Thex the acute genotoxicity of the heavy metal compound3 2 The formation of ground level ozone depends on the and NO were used for the investigation of the hourly contamination of aquatic ecosystems by heavy HgCl inx static systems. Mercuric chloride is toxic, intensity of solar radiation, the absolute concentration variation2 of NO, NO , NO and O . The variation of metals and pesticides has gained increasing attention solvable in water hence2 it canx penetrate3 the aquatic of NO and VOCs, and the ratio of NO to VOCs. oxidant OX (O and NO ) concentration with NO was in recentx decades. Chronic exposurex to and animals. Mutagenic3 studies2 with native fish speciesx Ground level ozone comes from two major sources also investigated, contributing to a better understanding accumulation of these chemicals in aquatic biota represent an important effort in determining the namely regional background ozone primarily from of the atmospheric sources of OX at this Kemaman area. can result in tissue burdens that produce adverse potential effects of toxic agents. This study was the influx of ozone from the stratosphere and in effects not only in the directly exposed organisms, carried out to evaluate the use of the micronucleus situ local ozone production mainly via precursors, 2. Materials and Methods but also in human beings. test (MN) for the estimation of aquatic pollution such as NO and VOC, emitted from variety of Fish providesx a suitable model for monitoring using marine edible fish under lab conditions. anthropogenic and natural sources (Clapp and 2.1. Site description aquatic genotoxicity and wastewater quality Jenkin, 2001). Ozone at high concentrations could because of its ability to metabolize xenobiotics and 2. Materials and methods induce several adverse effects on human health and Kemaman (4o12’ N, 103o18’ E) is situated in the accumulated pollutants. A micronucleus assay has the environment (Kampa and Castanas, 2007). Terengganu State, a developing Malaysian town been used successfully in several species (De Flora, 2.1. Sample Collection The concentration of photochemical oxidant (O and flanked by Kerteh Petrochemical Industrial Area et al., 1993, Al-Sabti and Metcalfe, 1995). The3 NO ) can be decreased by controlling their precursors; at the north and the industrializing and urbanizing micronucleus2 (MN) test has been developed The fish species selected for the present study Nitrogen Oxides, NO (NO and NO ) and VOCs (Geng Gebeng Industrial Area at the south (Fig. 1). In this together with DNA-unwindingx 2 assays as was collected from Pudhumadam coast of Gulf of et al., 2007). However, the efficiency of emission area, there are dominant sources of ozone precursors perspective methods for mass monitoring of Mannar, Southeast Coast of India. Therapon control also depends on the relationship between related to industrial activities and road traffic. clastogenicity and genotoxicity in fish and mussels jarbua belongs to the order Perciformes of the (Dailianis et al., 2003). family Theraponidae. The fish species, Therapon The MN tests have been successfully used as jarbua (6-6.3 cm in length and 4-4.25 g in weight) a measure of genotoxic stress in fish, under both was selected for the detection of genotoxic effect M. Ismail et al. / EnvironmentAsia 9(1) (2016) 1-8

Figure 1. Location of air quality monitoring station in Kemaman

2.2. Source of data 2.2. Source of data ozone measurement. The concentration of ozone

precursors, NOx (NO and NO2) were determined using In this study, the concentration of O3, NO, NO2, and NOx data consisting of 120 months from In thisJanuary study, 2000the concentration to December 2010of O3 ,(excluding NO, NO2 ,year the 2008 chemiluminescene due to the unavailable measurement of the dataprincipal, for that couple and NOx particulardata consisting year) ofacquired 120 months from thefrom Air January Quality Diviwithsion, state-of-the-art Malaysian Department microprocessor of Environment technology for for 2000 to DecemberSekolah Rendah 2010 Bukit(excluding Kuang year Station 2008 (Station due ID:monitoring CA 0002) highlocated and in Kemamanmedium levels District, of one nitrogen of the to the unavailableearliest operational of the data stations for that in particular Malaysia. year) The monitoringoxides (Teledyne network Modelswas installed 200A). operated For quality and control acquired maintainedfrom the Air by QualityAlam Sekitar Division, Malaysia Malaysian Sdn. Bh dand (ASMA) quality under assurance concession of the by air the monitoring Department data, of all DepartmentEnvironment of Environment Malaysia for (Afroz Sekolah et al., Rendah2003). Tropospheric monitoring ozone instruments concen trationswere calibrated data was regularlyrecorded byby Bukit Kuangusing Station a system (Station based onID: the CA Beer-Lambert 0002) located law forASMA. measuring For gas low monitoring ranges of such ozone as ozonein ambient and nitrogen air in Kemamanmanufactured District, one by Teledyneof the earliest Technologies operational Incorporated oxides, (Modelthe instruments 400E). A were 254 nmscheduled UV light to signalhave dailyis stations inpassed Malaysia. through The the monitoring sample cell networkwhere it iswas absorb autoed incalibration proportion using to the zero amount air (clean of ozone ambient present. air, free installed Everyoperated three and seconds, maintained a switching by Alam valve Sekitar alternates from measurement contaminant) between and thestandard sample gas stream concentration. and a Malaysia sampleSdn. Bhd that (ASMA) has been under scrubbed concession of ozone. by Thethe resultThe is instruments a true, stable haveozone been measurement. calibrated The manually Departmentconcentration of Environment of ozone Malaysia precursors, (Afroz NO etx (NO al., andusing NO 2its) were individual determined calibration using thegas chemiluminescene every two weeks. 2003). Troposphericmeasurement ozone principal, concentrations couple with data state-of-t was he-artThe microprocessorhourly data was technologyalso checked for for monitoring validation highbefore recorded byand using medium a system levels based of nitrogen on the Beer-Lambert oxides (Teledyn eit Modelscan be transferred 200A). For to quality the Department control and of Environment.quality law for measuringassurance oflow the ranges air monitoring of ozone data, in ambient all monitoring instruments were calibrated regularly by ASMA. air manufacturedFor gas by monitoring Teledyne Technologiessuch as ozone Incorporated and nitrogen oxides,2.3. Data the analysis instruments were scheduled to have daily (Model 400E).auto calibration A 254 nm using UV zerolight air signal (clean is ambientpassed air, free from contaminant) and standard gas through concentration.the sample cell The where instruments it is absorbedhave been calibrain tedIn manually order to using establish its individual the hourly calibration trend of selectedgas proportionevery to the two amount weeks. of Theozone hourly present. data Every was alsothree checked pollutants, for validation boxplot befowas reperformed it can be bytransferred using Microsoft to the Department of Environment. seconds, a switching valve alternates measurement Excel Spreadsheet 2013. In descriptive statistics, between the sample stream and a sample that has a boxplot is a convenient way of graphically depicting been scrubbed of ozone. The result is a true, stable groups of numerical data through their quartiles.

2 2.3. Data analysis

In order to establish the hourly trend of selected pollutants, boxplot was performed by using Microsoft Excel Spreadsheet 2013. In descriptive statistics, a boxplot is a convenient way of graphically depicting groups of numerical data through their quartiles. Boxplot is a graphic representation of a distribution by a rectangle, the ends of which mark the maximum and minimum values, and in which the median and first and third quartiles are marked by lines parallel to the ends. The individual box plot is a visual aid to examining key statistical properties of a variable such as median, mean and quartiles. Analyses of variance and correlation analysis (the correlation is significant at the 0.05 level (2-tailed)) were conducted using STATGRAPHICS® Centurion XVI.I statistical software package.

3. Results and Discussion

3.1. Hourly variation of O3, NO, NO2 and NOx concentrations

The 10 years (2000-2010, excluding year 2008) average diurnal variation of NO, NO2, NOx and O3 concentrations were shownM. Ismail in Fig.et al. 2. / EnvironmentAsia 9(1) (2016) 1-8

Figure 2. Hourly variation of mean values of NO, NO2, NOx, and O3 concentrations from 2000-2010* (excluding year 2008)

Boxplot is a graphic representation of a distribution by Based on Fig. 3, the diurnal cycle of ozone a rectangle, the ends of which mark the maximum and concentration reaches a peak during the middle of minimum values, and in which the median and first and the day, while there was a lower ozone concentration third quartiles are marked by lines parallel to the ends. during nighttime (Ramli et al., 2010). This is due to

The individual box plot is a visual aid to examining the photochemical reaction of O3 precursors, such as key statistical properties of a variable such as median, volatile organic compound (VOC), with ambient air mean and quartiles. Analyses of variance and correlation from natural sources and the long distance transport analysis (the correlation is significant at the0.05 level of NOx (Pires et al., 2012). The ozone concentration (2-tailed)) were conducted using STATGRAPHICS® slowly increases after the sun rises until it reached Centurion XVI.I statistical software package. its maximum during the daytime and then slowly decreases until the next morning. From 08:00 to 13:00- 3. Results and Discussion 14:00 hours, an increase in solar radiation results in the increasing of ozone concentration (Ulke and Maezzo,

3.1. Hourly variation of O3, NO, NO2 and NOx 1998). The average data of ozone concentration and concentrations solar radiation shows that the ozone concentration is highly correlated to solar radiation (J/m2.hr). It was The 10 years (2000-2010, excluding year 2008) found that the correlation coefficient between ozone and average diurnal variation of NO, NO2, NOx and O3 solar radiation was 0.67 from the statistical analysis, at concentrations were shown in Fig. 2. the 0.05 level (2-tailed).

3 Based on Fig. 3, the diurnal cycle of ozone concentration reaches a peak during the middle of the day, while there was a lower ozone concentration during nighttime (Ramli et al., 2010). This is due to the photochemical reaction of O3 precursors, such as volatile organic compound (VOC), with ambient air from natural sources and the long distance transport of NOx (Pires et al., 2012). The ozone concentration slowly increases after the sun rises until it reached its maximum during the daytime and then slowly decreases until the next morning. From 08:00 to 13:00-14:00 hours, an increase in solar radiation results in the increasing of ozone concentration (Ulke and Maezzo, 1998). The average data of ozone concentration and solar radiation shows that the ozone concentration is highly correlated to solar radiation (J/m2.hr). It was found that the correlation coefficient between M. Ismail et al. / EnvironmentAsia 9(1) (2016) 1-8 ozone and solar radiation was 0.67 from the statistical analysis, at the 0.05 level (2-tailed).

Figure 3. Hourly variation of mean values of solar radiation from 2000-2010* (excluding 2008)

The diurnal cycle of NO, NO2 and NOx are shaped like double waves. The morning peak of The diurnal cycle of NO, NO2 and NOx are These equations form a cycle with no net chemistry; NO2 occurs about two hours after the morning peak of NO (08:00). The O3 peak occurs at 14:00 shaped like double waves. The morning peak of NO2 the overall effect of reaction Eq. (2) is the reverse of occurs(Azmi about et al .,two 2010). hours It appearsafter the about morning 6 to peak 8 hours of NO after thereaction NO (08:00) Eq. (1). and These NO2 (10:00)reactionspeak. therefore After therepresent morning peak (08:00), NO diminishes until it reaches lower value at (13:00-14:00). It was found that, (08:00). The O3 peak occurs at 14:00 (Azmi et al., 2010). a closed system which has the overall effect of both NO and NO2 decreases correlate with an increase in O3 (Ramli et al., 2010). The increasing of It appears about 6 to 8 hours after the NO (08:00) and partitioning NOx between its component forms of NO NO2 has caused the decreasing of O3 concentrations (Ghazali et al., 2008). NO is a primary NO2 (10:00) peak. After the morning peak (08:00), and NO2, and oxidant (OX) between its component contaminant, whereas O3 and a large percentage of NO2 are secondary contaminants, formed through NO diminishes until it reaches lower value at (13:00- forms of O3 and NO2, but leaving a total mixing ratio a set of complex reaction. NO is converted to NO2 via a reaction with O3 as in Eq. (1). During 14:00). It was found that, both NO and NO2 decreases of both NOx and OX unchanged. During daytime daytime, NO2 is converted back to NO as a result of photolysis, leads to regeneration of O3 as in Eq. correlate(2). The withvertical an increasemixing layer in O 3of (Ramli also influe et al.,nced 2010). the air hours,pollution NO, concentrations NO2 and O3 (Bananare typically et al., equilibrated2013). on TheDuring increasing the day, of pollutants NO2 has wouldcaused be the diluted decreasing when miof xingthe layer timescale rises and of bea few limited minutes, to inside a condition nocturnal usually O concentrations (Ghazali et al., 2008). NO is a primary referred to as photo stationary state. NO, NO and O planetary3 boundary layer (NPBL) during nighttime. Emitted pollutants such as NO and NO2 are kept 2 3 contaminant,beneath this inversion,whereas O which3 and maya large cause percentage the hourly of NO xconcentrationsconcentration toare increase related during by the the expression night [NO]. NO(Han2 areet secondaryal., 2011) contaminants, formed through a [O3]/[NO2] = J2/k1, where J2 is the rate of NO2 set of complex reaction. NO is converted to NO2 via a photolysis and k1 is the rate coefficient for the reaction reaction3.2. Chemical with O 3coupling as in Eq. of (1). O 3During, NO and daytime, NO2 NO2 is of NO with O3 (Han et al., 2011). converted back to NO as a result of photolysis, leads The variation of the mean value of J2/k1 over time, to regenerationThe inter of O conversion3 as in Eq. (2). of O The3, NO vertical and NO mixing2 under obtainedatmospheric using conditions 10 years datais generally at Kemaman dominated of NO, NO2 layerby the of alsofollowing influenced reactions the air(Kenty pollution et al .,concentrations 2007) and O3 is shown in Fig. 4. The mean values of J2/k1 (Banan et al., 2013). During the day, pollutants would vary between 3.225 and 12.869 ppb and the maximum be dilutedNO when + O mixing3 layer NO2 rises+ O2 and be limited to value occurred (1) at 15:00. This provides adequate inside nocturnalNO2 + hv planetary (+O2) boundary NO + Olayer3 (NPBL) description (2) of diurnal averaged observations, consistent during nighttime. Emitted pollutants such as NO and with the chemical coupling of these species being These equations form a cycle with no net chemistry; the overall effect of reaction Eq. (2) is NO2 are kept beneath this inversion, which may cause dominated by reactions Eq. (1) and Eq. (2). the reverse of reaction Eq. (1). These reactions therefore represent a closed system which has the the hourly NOx concentration to increase during the Fig.5 shows the variation in daytime O3 concentration night (Han et al., 2011) as a function of the NO2/NO ratio. It was found that

the level of O3 increases with an increase in NO2/

3.2. Chemical coupling of O3, NO and NO2 NO ratio. O3 increases rapidly with a small value of

NO2/NO ratio, this may be implicated that when O3

The inter conversion of O3, NO and NO2 under was at low levels, the reactions of production of O3 atmospheric conditions is generally dominated by the was dominated reaction (Han et al., 2011). When O3 following reactions (Kenty et al., 2007) reached at about 35 ppb, it tended to remains relatively

stable. This shows that at higher levels, O3 is close to NO + O3 NO2 + O2 (1) reaching a photo stationary state. The output shows NO2 + hv (+O2) NO + O3 (2) the results of fitting a logarithmic-X model to describe

4 overall effect of partitioning NOx between its component forms of NO and NO2, and oxidant (OX) between its component forms of O3 and NO2, but leaving a total mixing ratio of both NOx and OX unchanged. During daytime hours, NO, NO2 and O3 are typically equilibrated on the timescale of a few minutes, a condition usually referred to as photo stationary state. NO, NO2 and O3 concentrations are related by the expression [NO].[O3]/[NO2] = J2/k1, where J2 is the rate of NO2 photolysis and k1 is M. Ismail et al. / EnvironmentAsia 9(1) (2016) 1-8 the rate coefficient for the reaction of NO with O3 (Han et al., 2011).

overall effect of partitioning NOx between its component forms of NO and NO2, and oxidant (OX) between its component forms of O3 and NO2, but leaving a total mixing ratio of both NOx and OX unchanged. During daytime hours, NO, NO2 and O3 are typically equilibrated on the timescale of a few minutes, a condition usually referred to as photo stationary state. NO, NO2 and O3 concentrations are related by the expression [NO].[O3]/[NO2] = J2/k1, where J2 is the rate of NO2 photolysis and k1 is the rate coefficient for the reaction of NO with O3 (Han et al., 2011).

Figure 4. Variation of mean values of J2/k1

The variation of the mean value of J2/k1 over time, obtained using 10 years data at Kemaman the relationship between O3 concentrations and NO2/ during the day and then decreases until the next morning. NO. Theof equationNO, NO2 andof theO3 isfitted shown inmodel Fig. is4. TheO (ppb) mean =values This of Jis2/k due1 vary to between the photochemical 3.225 and 12.869 O3 formationppb (Pires and the maximum value occurred at 15:00.3 This provides adequate description of diurnal averaged 13.6992observations, + 12.3397*ln consistent (NO2/NO). with theSince chemical the result couplin ofg of etthese al., species2012). beingFig. 7 dominated shows the by variation reactions of [NO2]/[OX]. P-value Eq.from (1) the and ANOVA Eq. (2). is less than 0.05, there is a A smaller ratio of [NO2]/[OX] is due to the higher statistically significant relationship between O3 and concentration of O3 during the day. This difference in

NO2/NO at the 95.0% confidence level. The logarithmic the partitioning of NO2 and O3 may be related to the rate function can be used to forecast the [O3] during the of chemical processes or the time available for them daytime. The correlation coefficient equals to 0.70, to occur. For instance, the higher ratio of [NO2]/[OX] indicating a moderately strong relationship between was due to the lower O3 concentration during the day. the variables. 3.4. Local and regional contributions to oxidant 3.3. Diurnal variation of [OX] The variation of OX concentration against the

Fig. 6 shows the variation in the mean value of OX level of NOx is shown in Fig. 8. The total OX appears concentration. OX concentration shows a mid-day peak to increase linearly with NOx over the entire range The variation of the mean value of J2/k1 over time, obtained using 10 years data at Kemaman and lower nighttime concentrations which is similar to considered, such that the level of OX at Kemaman has of NO, NO2 and O3 is shown in Fig. 4. The mean values of J2/k1 vary between 3.225 and 12.869 ppb the variationand the of Omaximum3 concentration. value occurred The OX at concentration15:00. This provides NO adequatex-independent description contribution of diurnal averaged and NO x-dependent slowly raisesobservations, after theconsistent sunrise, with reaches the chemical a maximum coupling of contribution.these species being The dominatedNOx-independent by reactions contribution can Eq. (1) and Eq. (2).

Figure 5. Relationship of O3 concentration with the [NO2]/[NO] ratio from 2000-2010* (excluding year 2008)

5 Fig.5 shows the variation in daytime O3 concentration as a function of the NO2/NO ratio. It was found that the level of O3 increases with an increase in NO2/NO ratio. O3 increases rapidly with a small value of NO2/NO ratio, this may be implicated that when O3 was at low levels, the reactions of production of O3 was dominated reaction (Han et al., 2011). When O3 reached at about 35 ppb, it tended to remains relatively stable. This shows that at higher levels, O3 is close to reaching a photo stationary state. The output shows the results of fitting a logarithmic-X model to describe the relationship between O3 concentrations and NO2/NO. The equation of the fitted model is O3 (ppb) = 13.6992 + 12.3397*ln (NO2/NO). Since the result of P-value from the ANOVA is less than 0.05, there is a statistically significant relationship between O3 and NO2/NO at the 95.0% confidence level. The logarithmic function can be used to forecast the [O3] during the daytime. The correlation coefficient equals to 0.70, indicating a moderately strong relationship between the variables.

3.3. Diurnal variation of [OX]

Fig. 6 shows the variation in the mean value of OX concentration. OX concentration shows a mid-day peak and lower nighttime concentrations which is similar to the variation of O3 concentration. The OX concentration slowly raises after the sunrise, reaches a maximum during the day and then decreases until the next morning. This is due to the photochemical O3 formation (Pires et al., 2012). Fig. 7 shows the variation of [NO2]/[OX]. A smaller ratio of [NO2]/[OX] is due to the higher concentration of O3 during the day. This difference in the partitioning of NO2 and O3 may be related to the rate of chemical processes or the time available for them to occur. For instance, the higher ratio of [NO2]/[OX] wasM. due Ismail to the et al. lower / EnvironmentAsia O3 concentration 9(1) (2016) during 1-8 the day.

Figure 6. Variation of mean values of OX Figure 7. Variation of mean values of NO2/OX ratio

3.4. Local and regional contributions to oxidant be considered as a regional contribution which equates 3.5. Correlations between O3 and NOx to the regionalThe variationbackground of OX of concentrationO3 level, while against the the level of NOx is shown in Fig. 8. The total OX NOxappears-dependent to increase contribution linearly can with be considered NOx over asthe local entire range Fig. considered, 9 shows thatsuch the that concentration the level of OXof O at3 and NOx contributionKemaman and has is NOcorrelatedx-independent with the contribution level of primary and NO werex-dependent linearly contribution. correlated. The NOcorrelationx-independent coefficient pollution.contribution The result can of be this considered study is similar as a regional as performed contri butionequals which to -0.165 equates, indicating to the regional a relatively background weak relationship of by ClappO3 level, and while Jenkin the (2001). NOx-dependent contribution can bebetween considered the variables as local (Ocontribution3 and NOx). and A weak is correlation

correlatedThe local withOX thesource level has of probableprimary pollution.contributions The resultbetween of this O study3 and isNO similarx indicates as performed that Kemaman by area is fromClapp direct and NO Jenkin2 emission, (2001). thermal reaction of NO probably not NOx-sensitive but possibly VOC-sensitive. with O2 at high NOx and common source emission of This inverse relationship of O3 and NOx is due to the species which promote NO to NO2 conversion. The titration of O3 during the daytime (Banan et al., 2013; regional contribution to O3 concentration was known Nishanth et al., 2014). Based on Fig. 10, the NO2/NOx to be at about 18.22 ppb according to the intercept of ratio decreased greatly as NOx increased that could be the relationship between OX concentration and NOx newly emitted could also support the VOC-sensitive concentration. nature in Kemaman. This finding is corresponding as

Figure 8. Relationship betwween [OX] with the level of [NO ] from 2000-2010* (excluding year 2008)

The local OX source has probable contributions from direct NO2 emission, thermal reaction of NO with O2 at high NOx and common source emission6 of species which promote NO to NO2 conversion. The regional contribution to O3 concentration was known to be at about 18.22 ppb according to the intercept of the relationship between OX concentration and NOx concentration.

3.5. Correlations between O3 and NOx

Fig. 9 shows that the concentration of O3 and NOx were linearly correlated. The correlation coefficient equals to -0.165, indicating a relatively weak relationship between the variables (O3 and NOx). A weak correlation between O3 and NOx indicates that Kemaman area is probably not NOx- sensitive but possibly VOC-sensitive. This inverse relationship of O3 and NOx is due to the titration of O3 during the daytime (Banan et al., 2013; Nishanth et al., 2014). Based on Fig. 10, the NO2/NOx ratio decreased greatly as NOx increased that could be newly emitted could also support the VOC-sensitive nature in Kemaman. This finding is corresponding as found by Song et al. (2011). VOC was emitted from the industrialized area and may also be emitted by traffic, and more detailed relationship among NOx, VOC and O3 in this area need to be explored through future studies. The local OX source has probable contributions from direct NO2 emission, thermal reaction of NO with O2 at high NOx and common source emission of species which promote NO to NO2 conversion. The regional contribution to O3 concentration was known to be at about 18.22 ppb according to the intercept of the relationship between OX concentration and NOx concentration.

3.5. Correlations between O3 and NOx

Fig. 9 shows that the concentration of O3 and NOx were linearly correlated. The correlation coefficient equals to -0.165, indicating a relatively weak relationship between the variables (O3 and NOx). A weak correlation between O3 and NOx indicates that Kemaman area is probably not NOx- sensitive but possibly VOC-sensitive. This inverse relationship of O3 and NOx is due to the titration of O3 during the daytime (Banan et al., 2013; Nishanth et al., 2014). Based on Fig. 10, the NO2/NOx ratio decreased greatly as NOx increased that could be newly emitted could also support the VOC-sensitive nature in Kemaman. This finding is corresponding as found by Song et al. (2011). VOC was emitted from the industrialized area and may also be emitted by traffic, and more detailed relationship among NOx, VOC and O3 in this area M.need Ismail to beet al. explored / EnvironmentAsia through 9(1)future (2016) studies. 1-8

Figure 9. Correlations between [O3] and [NOx] Figure 10. Relationship NO2/NOx ratio from 2000-2010* from 2000-2010* (excluding year 2008) (excluding year 2008) found by Song et al. (2011). VOC was emitted from the References industrialized area and may also be emitted by traffic, Afroz R, Hassan MN, Ibrahim NA. Review of air pollution and more detailed relationship among NOx, VOC and O3 in this area need to be explored through future and health impacts in Malaysia. Environmental Research studies. 2003; 92(2): 71-77. Azmi SZ, Latif MT, Ismail AS, Juneng L, Jemain AA. Trend and status of air quality at three different monitoring 4. Conclusions stations in the Klang Valley, Malaysia. Air Quality, Atmosphere and Health 2010; 3(1): 53-64. This study analyses the concentrations of NO, NO2, Banan N, Latif MT, Juneng L, Ahamad F. Characteristics NOx and O3 for 10 years from 2000 to 2010 (excluding of surface ozone concentrations at stations with different year 2008). The results indicate that the diurnal cycle backgrounds in the Malaysian Peninsula. Aerosol and of ozone concentration has a mid-day peak (14:00) Air Quality Research 2013; 13(3): 1090-106. and lower nighttime concentrations. The ozone Clapp LJ, Jenkin ME. Analysis of the relationship between concentration slowly rises after the sun rises (08:00), ambient levels of O3, NO2, and NO as a function of NOx reaching a maximum during daytime and then decreases in the UK. Atmospheric Environment 2001; 35(36): 6391-405. until the next morning. This is due to the photochemical Geng F, Zhao C, Tang X, Lu G, Tie X. Analysis of ozone of ozone formation. In this study, it was also found a and VOCs measured in Shanghai: A case study. weak linear relationship between O3 and NOx, suggesting Atmospheric Environment 2007; 41(5): 989-1001. that this Kemaman area is not NOx sensitive but Ghazali NA, Ramli NA, Yahaya AS, Yusof NF, Sansuddin possibly VOC-sensitive area. A logarithmic relationship N, Madhoun WA. Temporal analysis and prediction of between O3 concentration and [NO2]/[NO] ratio was ozone concentrations in Gombak, Selangor. International also found which could be useful in [O3] forecasting Conference on Construction and Building Technology and air pollution control strategies. The level of [OX] 2008; 221-32. Han S, Bian H, Feng Y, Liu A, Li X, Zeng F, Zhang X. Analysis is influenced by NO2-independent and NO2-dependent contributions. The former is due to regional background of the relationship between O3, NO and NO2 in Tianjin, China. Aerosol and Air Quality Research 2011; 11: 128-39. O3 concentration and the latter correlates to the local Kampa M, Castanas E. Human health effects of air pollution. level of primary pollution. The regional background O3 Environmental Pollution 2007; 151(2): 362-67. concentration in Kemaman is about 18.22 ppb Kenty KL, Poor ND, Kronmiller KG, McClenny W, King C, Atkeson T, Campbell SW. Application of CALINE4

Acknowledgements to roadside NO/NO2 transformations. Atmospheric Environment 2007; 41(20): 4270-80. This study was funded by Fundamental Research Grant Nishanth T, Praseed KM, Kumar MKS, Valsaraj KT.

Scheme (FRGS) FRGS/2/2013/STWN01/UMT/02/1 (VOT Observational study of surface O3, NOx, CH4 and total 59312) and Universiti Malaysia Terengganu Scholarship NMHCs at Kannur, India. Aerosol and Air Quality Scheme (BUMT). The authors would also like to thank the Research 2014; 14: 1074-88. Air Quality Division, Malaysian Department of Environment (DOE) for the air quality data.

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Pires JCM, Alvim-Ferraz MCM, Martins FG. Surface ozone behaviour at rural sites in Portugal. Atmospheric Research 2012; 104-105: 164-71. Ramli NA, Ghazali NA, Yahaya AS. Diurnal fluctuations of ozone concentrations and its precursors and prediction of ozone using multiple linear regressions. Malaysian Journal of Environmental Management 2010; 11(2): 57-69. Song F, Shin JY, Jusino-Atresino R, Gao Y. Relationship

among the springtime ground-level NOx, O3 and NO3 in the vicinity of highways in the US East Coast. Atmospheric Pollution Research 2011; 2(3): 374-83. Ulke AG, Mazzeo NA. Climatological aspects of the daytime mixing height in Buenos Aires City, Argentina. Atmospheric Environment 1998; 32(9): 1615-22.

Received 21 April 2015 Accepted 8 June 2015

Correspondence to Dr. Marzuki Ismail School of Marine Science and Environment, Universiti Malaysia Terengganu 21030 Kuala Terengganu, Terengganu, Malaysia Tel: +60 9668 3548 Fax: +60 9669 4669 E mail: [email protected]

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