Real-Time Detection and Mixing State of Methanesulfonate in Single Particles at an Inland Urban Location during a Phytoplankton Bloom

Dimethyl sulfide (DMS), produced by oceanic phytoplankton, is oxidized to form methanesulfonic acid (MSA) and sulfate, which influence particle chemistry and hygroscopicity. Unlike sulfate, MSA has no known anthropogenic source making it a useful tracer for ocean-derived biogenic sulfur. Despite numerous observations of MSA, predominately in marine environments, the production pathways of MSA have remained elusive highlighting the need for additional measurements, particularly at inland locations. During the Study of Organic Aerosols in Riverside, CA from July-August 2005, MSA was detected in submicrometer and supermicrometer particles using real-time, single-particle mass spectrometry. MSA was detected due to blooms of DMS-producing organisms along the California coast. The detection of MSA depended on both the origin of the sampled air mass as well as the concentration of oceanic chlorophyll present. MSA was mainly mixed with coastally emitted particle types implying that partitioning of MSA occurred before transport to Riverside. Importantly, particles containing vanadium had elevated levels of MSA compared to particles not containing vanadium, suggesting a possible catalytic role of vanadium in MSA formation. This study demonstrates how anthropogenic, metal-containing aerosols can enhance the atmospheric processing of biogenic emissions, which needs to be considered when modeling coastal as well as urban locations

Prevalence of HTN, pre-HTN and normotensive for adults aged 35 to 64 years from 1982 to 2010.

<p>HTN, hypertension; pre-HTN, pre-hypertension; 95% CI, 95% confidence interval.</p>*<p>Age- and sex- adjusted percentages.</p>†<p>Age- adjusted percentages for men or women. Adjustment was conducted with the 2000 Chinese National Census population by the direct method.</p

Trends in mean SBP and DBP among adults in different sex and age group, 1982 to 2010.

<p>Trends in mean SBP and DBP among adults in different sex and age group, 1982 to 2010.</p

Mean SBP and DBP (mm Hg) for adults aged 35 to 64 years from 1982 to 2010.

<p>SBP, systolic blood pressure; DBP, diastolic blood pressure; 95% CI, 95% confidence interval.</p>*<p>Age- and sex- adjusted mean SBP or DBP values.</p>†<p>Age- adjusted mean SBP or DBP values for men or women. Adjustment was conducted with the 2000 Chinese National Census population by the direct method.</p

Trends in prevalence of HTN among adults in different sex and age group, 1982 to 2010.

<p>Trends in prevalence of HTN among adults in different sex and age group, 1982 to 2010.</p

Change in distribution of BP categories, 1982 to 2010.

<p>Change in distribution of BP categories, 1982 to 2010.</p

Awareness, treatment and control of HTN for adults aged 35 to 64 years from 1982 to 2010.

<p>HTN, hypertension; 95% CI, 95% confidence interval.</p>*<p>Age-and sex- adjusted percentages.</p>†<p>Age- adjusted percentages for men or women. Adjustment was conducted with the 2000 Chinese National Census population by the direct method.</p

Trends in awareness, treatment, control of HTN among adults in different sex and age group, 1982 to 2010.

<p>Trends in awareness, treatment, control of HTN among adults in different sex and age group, 1982 to 2010.</p

Characteristics of the population in the study.

<p>HTN, hypertension; BMI, body mass index.</p><p>–Without data.</p>*<p>P value for trend.</p

Results of logistic regression analyses of risk factors for prevalence, awareness, treatment and control of HTN.

<p>HTN, hypertension; 95% CI, 95% confidence interval.</p>*<p>No data about marital status, education level and family history of HTN in the 1982’s survey. The logistic regression analyses were conducted using data from 1998 to 2010.</p