Overexposure to ultraviolet (UV) radiation has increased skin cancer incidence and the risk of sunburns, especially during the summer months.
Identify the frequency and factors associated with sunburns in a sample of beachgoers in the northern coast of Peru.
We conducted a secondary data analysis of a previous study that assessed the awareness, behavior and attitudes concerning sun exposure among beachgoers. We included adults between 18 and 59 years who went to a beach in northern Peru during summer (March 2018). Three generalized linear models of the Poisson family were constructed to evaluate the factors associated with having had at least one sunburn last summer. All regression models reported the adjusted prevalence ratio (aPR) with their respective 95% confidence interval (95% CI).
Of a total of 402 participants, 225 (56.0%) had one to five sunburns and 25 (6.2%) had six or more. Beachgoers who were 1–15 days (aPR: 1.16, 95% CI [1.05–1.27]) or more than 15 days (aPR: 1.22, 95% CI [1.09–1.36]) exposed to the sun on the beach had a higher frequency of at least one sunburn. The non-regular wearing of a hat or cap also increased the frequency of sunburns (aPR: 1.06, 95% CI [1.01–1.12]). In contrast, those who had Skin Phototype III (aPR: 0.94, 95% CI [0.88–0.99]) or IV (aPR: 0.69, 95% CI [0.63–0.75]) had a lower frequency of sunburns.
Three out of five beachgoers had one or more sunburns in the last summer. The factors associated with a higher frequency were the time of sun exposure at the beach and the non-regular use of a hat or cap. Type III–IV skin phototypes were associated with a lower sunburn frequency.
Skin cancer incidence has increased in the last decades (
Peru is one of the countries with the highest ultraviolet (UV) radiation due to its proximity to the equator (
Current evidence has shown the relationship between overexposure to UV radiation and skin cancer (
Previous studies conducted in adult populations have reported a frequent lifetime history of at least one sunburn (
This study aimed to determine the frequency and factors associated with sunburns in a sample of beachgoers in the northern coast of Peru.
This is a secondary data analysis of a previous study that assessed the awareness, behavior and attitudes concerning sun exposure among beachgoers in the northern coast of Peru (
We selected from the database the adults surveyed during their visit to Pimentel, which has one of the most crowded beaches in Lambayeque. This region has a semi-warm and tropical-dry climate, with temperatures peaks of 30 °C since 2014 (
For the primary study, a total of 410 participants ≥18 years old were enrolled using a convenience sampling strategy. The research team applied the “Beach Questionnaire” during the summer season (March 2018), between 08:00 and 16:00 hours. More information about the study population, context and procedures has been previously described in this journal (
The outcome variable “sunburn” was defined as an episode of painful reddening of the skin after sun exposure in the last summer (
The following independent variables were included in the analysis: (1) Sociodemographic variables: age (young adult: 18–29 years, and adult: 30–59 years), sex (male and female), nationality, level of education (None/school and higher education), marital status (single/widowed/divorced/separated and married/cohabiting); (2) Skin phototype from the Fitzpatrick model and classified into four categories (I–IV) according to the erythema and tanning response after one hour of sun exposure in the summer (
According to the history of sunburns in the last summer (none and ≥1 sunburn ). For categorical variables, we used Chi-square and Fisher tests. To assess the factors associated with having had at least one sunburn in the last summer (dichotomous variable), we constructed three generalized linear models (GLM) of the Poisson family with a log link function and robust standard errors. We decided to use the Poisson family instead of logistic regression to avoid overestimating the calculated associations, especially because the prevalence of sunburns (outcome) was >10% (
All regression models reported the adjusted prevalence ratio (aPR) with their respective 95% confidence intervals (95% CI). The statistical analysis was carried out using the statistical package Stata v15.0 (StataCorp, College Station, TX, USA).
The Institutional Review Board of the Hospital San Bartolomé (RCEI-40) in Lima, Peru, approved the primary study. Participation in the survey was voluntary, and all the participants provided their oral consent.
We analyzed a total of 402 beachgoers of both sexes. A total of 232 (57.7%) were female, 152 (37.8%) had no sunburn, 225 (56.0%) had one to five sunburns and 25 (6.2%) had six or more.
Variables | Sunburn history | ||
---|---|---|---|
None ( |
≥1 ( |
||
Age | 0.543 |
||
Young adult | 81 (36.5) | 141 (63.5) | |
Adult | 71 (39.4) | 109 (60.6) | |
Sex | 0.528 |
||
Male | 62 (36.1) | 110 (63.9) | |
Female | 90 (39.1) | 140 (60.9) | |
Marital status | 0.635 |
||
Single/Widowed/Divorced/separated | 90 (38.8) | 142 (61.2) | |
Married or cohabiting | 62 (36.5) | 108 (63.5) | |
Nationality | 0.403 |
||
Peru | 148 (37.6) | 246 (62.4) | |
Argentina | 2 (100.0) | 0 (0.0) | |
Colombia | 1 (33.3) | 2 (66.7) | |
Ecuador | 1 (50.0) | 1 (50.0) | |
Mexico | 0 (0.0) | 1 (100.0) | |
Level of education | 0.606 |
||
None or school | 58 (39.5) | 89 (60.5) | |
Higher education | 94 (36.9) | 161 (63.1) | |
Skin phototype | <0.001 |
||
I | 11 (18.3) | 49 (81.7) | |
II | 22 (27.8) | 57 (72.2) | |
III | 47 (28.8) | 116 (71.2) | |
IV | 72 (72.0) | 28 (28.0) | |
Days spent sunbathing on the beach | 0.001 |
||
None | 32 (59.3) | 22 (40.7) | |
1 - 15 days | 101 (35.8) | 181 (64.2) | |
More than 15 days | 19 (28.8) | 47 (71.2) | |
Hours per day exposed to the sun on the beach | 0.025 |
||
Less than 30 minutes | 35 (52.2) | 32 (47.8) | |
30 minutes to one hour | 35 (37.2) | 59 (62.8) | |
More than one hour | 82 (34.0) | 159 (66.0) | |
Non-regular using of a beach umbrella | 88 (39.1) | 137 (60.9) | 0.544 |
Non-regular wearing of a hat or cap | 76 (35.7) | 137 (64.3) | 0.350 |
Non-regular wearing long-sleeved clothing | 120 (37.0) | 204 (63.0) | 0.514 |
Non-regular avoiding of sun exposure during the midday | 75 (32.1) | 159 (68.0) | 0.005 |
Non-regular using of sunscreen with a SPF ≥ 15 | 50 (34.2) | 96 (65.8) | 0.266 |
Chi2 test.
Fisher exact test.
SPF: Sun protection factor.
Variables | Model 1 | Model 2 | Model 3 | ||||||
---|---|---|---|---|---|---|---|---|---|
aPR | 95% CI | aPR | 95% CI | aPR | 95% CI | ||||
Age (adults) | 0.96 | [0.90–1.03] | 0.300 | 0.98 | [0.91–1.05] | 0.493 | 0.98 | [0.93–1.05] | 0.614 |
Sex (females) | 0.98 | [0.92–1.04] | 0.527 | 1.01 | [0.95–1.07] | 0.895 | 0.99 | [0.94–1.05] | 0.786 |
Marital status | |||||||||
Single | Ref. | Ref. | Ref. | ||||||
Married or cohabiting | 1.04 | [0.97–1.11] | 0.291 | 1.03 | [0.96–1.10] | 0.380 | 0.99 | [0.93–1.05] | 0.662 |
Leve of education | |||||||||
None or school | Ref. | Ref. | Ref. | ||||||
Higher education | 1.01 | [0.95–1.08] | 0.705 | 1.03 | [0.97–1.09] | 0.403 | 0.99 | [0.93–1.04] | 0.643 |
Days spent sunbathing on the beach in the last two summers | |||||||||
None | Ref. | Ref. | |||||||
1–15 days | 1.14 | [1.03–1.26] | 0.011 | ||||||
More than 15 days | 1.19 | [1.06–1.35] | 0.004 | ||||||
Hours spent sunbathing on the beach in the last two summers | |||||||||
Less than 30 minutes | Ref. | Ref. | |||||||
30 minutes to one hour | 1.06 | [0.96–1.17] | 0.245 | 1.08 | [0.98–1.19] | 0.122 | |||
More than one hour | 1.05 | [0.96–1.15] | 0.313 | 1.06 | [0.97–1.16] | 0.200 | |||
Non-regular using of a beach umbrella | 0.98 | [0.92–1.04] | 0.411 | 0.98 | [0.93–1.04] | 0.509 | |||
Non-regular wearing of a hat or cap | 1.02 | [0.96–1.08] | 0.551 | ||||||
Non-regular wearing long-sleeved clothing | 1.01 | [0.93–1.09] | 0.856 | 1.02 | [0.95–1.10] | 0.609 | |||
Non-regular avoiding of sun exposure during midday | 1.07 | [1.01–1.14] | 0.019 | 1.04 | [0.99–1.10] | 0.146 | |||
Non-regular using of sunscreen with a SPF ≥ 15 | 1.04 | [0.98–1.11] | 0.203 | 1.05 | [1.00–1.11] | 0.072 | |||
Skin phototype | |||||||||
I | Ref. | ||||||||
II | 0.95 | [0.89–1.02] | 0.175 | ||||||
III | |||||||||
IV |
aPR, Adjusted prevalence ratio; SPF, Sun protection factor; 95% CI, 95% confidence intervals.
In our study sample, we found different factors associated with sunburns in people who went to a beach in northern Peru. Having skin phototype III or IV was associated with a lower frequency of sunburn. However, going to the beach for 1 to 15 days, more than 15 days, and not wearing a hat or cap regularly were associated with a higher frequency.
More than a half (62.2%) of the beachgoers reported having had at least one sunburn in the last two summers in our study sample. A previous study in beachgoers and skaters from Costa del Sol, Spain, found a lower sunburn frequency (46.9% and 56.8%, respectively) (
Regarding the use of hats or caps, in our study, the non-regular use of these accessories was associated with a higher prevalence of sunburn. This result is explained by a previous study by Backes C et al (2018), in which the effectiveness of using hats for sun protection was assessed. They found that not wearing this accessory and inadequate face protection in the midday hours of summer were associated with receiving higher doses of solar ultraviolet radiation (UVR) (
Regarding the frequency of sunbathing on the beach in the last two summers, bathers who sunbathed at least one day had a higher frequency of sunburns. This frequency was even higher among those who sunbathed for more than 15 days. These are expected results since one person is more vulnerable to sunburns if there are no adequate sun protection measures and more prolonged sun exposure (
Beachgoers with a skin phototype type III–IV showed a lower frequency of sunburns in the last two summers. An explanation for this result is based on the Fitzpatrick’s study which showed that the skin phototype IV rarely suffers sunburns and develops a tan more easily. In addition, although adults with skin phototype III may also have some risk of suffering from sunburns, its risk is lower than skin phototypes type I and II (
Like previous studies (
In Peru, every first Sunday of February, we celebrate “El día del lunar”, a national awareness day where medical campaigns are carried out along with informative talks. These activities’ main objective is to raise awareness about the health risks of prolonged sun exposure (
Peru must adopt evidence-based strategies. For example, in Australia, some cross-sectional studies assessed the impact of sun protection campaigns. These campaigns are delivered through the media during the summer, with favorable results reported (
The present study has some limitations. First, the possibility of social desirability bias. The beachgoers could have responded according to the sun protection measures presented in the media or their previous knowledge, reporting sun protection habits that they do not practice. Second, we did not assess the effect of some variables that could potentially influence our study results, such as current or past illnesses and a family history of skin cancer. Third, our study does not represent the Pimentel district’s demography because many beachgoers come to vacation from other cities, regions, and countries during the summer. The study also does not necessarily represent the expected frequencies to be found in subsequent studies since population and climatic conditions may vary. Fourth, due to the cross-sectional design of the study, we cannot infer causality between the variables of interest.
Despite these limitations, this study is one of the first in the local context to assess factors associated with sunburns. There are previous studies that aimed to describe the knowledge, habits, and attitudes about photoprotection. However, they were conducted in different populations, such as outpatients, farmers, and company workers (
Three out of five beachgoers had experience one or more sunburns in the last summer. The factors associated with a higher frequency were the time of sun exposure and the non-regular use of a hat or cap at the beach. Skin phototypes III–IV were associated with a lower frequency of sunburn.
To Sara Burgos, Luz Vargas, Jhosuny Perez, Otto Vargas and Ruth Burgos, who participated in the primary study’s data collection.
The authors declare that they have no competing interests.
The following information was supplied regarding data availability:
The database is available at figshare: Toro-Huamanchumo, Carlos (2018): Dataset.eng - Sun exposure. figshare. Dataset.